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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

Studies of experimental bacterial translocation /

Stenbäck, Anders, January 2005 (has links)
Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 4 uppsatser.
2

Exogenous Glucagon-like Peptide-2 in Neonatal Piglet Models of Short Bowel Syndrome: Does the Intestinal Adaptive Response Vary with Remnant Intestinal Anatomy?

Suri, Megha 19 March 2013 (has links)
Glucagon-like peptide-2 (GLP-2) augments intestinal adaptation in animal models of short bowel syndrome (SBS) and in adult patients with SBS. However, GLP-2 has not been used as a therapy for pediatric SBS. In this thesis, it is hypothesized that exogenous GLP-2 therapy will improve outcomes of intestinal adaptation in proximal intestinal resection (JI) and distal intestinal resection (JC) neonatal piglet models of SBS. Improvements in morphological parameters (increased small intestinal length) and histological parameters (increased jejunal villus length or jejunal crypt depth) of intestinal adaptation in JI and JC neonatal piglets treated with GLP-2 were observed. However, improved clinical outcomes (fewer days of diarrhea, fewer days on parenteral nutrition, more days on enteral nutrition alone) were only observed in GLP-2 treated JC animals. Since the JC anatomical subtype (no remnant ileum) represents the majority of clinical cases of neonatal SBS, these results support a potential role for GLP-2 therapy in pediatric SBS.
3

Exogenous Glucagon-like Peptide-2 in Neonatal Piglet Models of Short Bowel Syndrome: Does the Intestinal Adaptive Response Vary with Remnant Intestinal Anatomy?

Suri, Megha 19 March 2013 (has links)
Glucagon-like peptide-2 (GLP-2) augments intestinal adaptation in animal models of short bowel syndrome (SBS) and in adult patients with SBS. However, GLP-2 has not been used as a therapy for pediatric SBS. In this thesis, it is hypothesized that exogenous GLP-2 therapy will improve outcomes of intestinal adaptation in proximal intestinal resection (JI) and distal intestinal resection (JC) neonatal piglet models of SBS. Improvements in morphological parameters (increased small intestinal length) and histological parameters (increased jejunal villus length or jejunal crypt depth) of intestinal adaptation in JI and JC neonatal piglets treated with GLP-2 were observed. However, improved clinical outcomes (fewer days of diarrhea, fewer days on parenteral nutrition, more days on enteral nutrition alone) were only observed in GLP-2 treated JC animals. Since the JC anatomical subtype (no remnant ileum) represents the majority of clinical cases of neonatal SBS, these results support a potential role for GLP-2 therapy in pediatric SBS.
4

Morphogenesis and morphology of intestinal villi

Partridge, Roland William January 2017 (has links)
Paediatric intestinal failure following bowel resection causes significant morbidity and mortality. There is a pressing need for improved treatment modalities. Following loss of bowel, the remaining intestine undergoes a period of adaptation, characterised by an increase in height of the intestinal villi. Better understanding the factors that govern the formation and growth of villi may lead to therapeutic interventions that amplify the intrinsic adaptation response. This thesis aims to explore the processes by which intestinal villi form during embryological development, the contribution of intestinal stem cells to this, and candidate signalling pathways that may yield insights into new therapeutic interventions for patients with intestinal failure. Abstract: Aim I will examine the morphogenesis and morphology of intestinal villi by investigating three themes: 1) Villus morphogenesis: When and where do villi form along the gut tube? Can this process be quantified, both in vivo and in vitro? Is this initiated by a dominolike signaling-cascade along the bowel, or location-specific intrinsic triggers? 2) Stem cells: What is the spatiotemporal appearance of the Lgr5-expressing intestinal stem cells during development? How does this relate to the process of villus morphogenesis? 3) Signalling pathways: Can a genetic mutation mouse model help elucidate pathways by which post bowel resection adaptation might occur? Can this be used to help identify potential intestinotrophic agents? Abstract: Materials and Methods Three mice models were used as the foundation for this work. Embryonic tissue was analysed from wild-type CD1 and Lgr5-eGFP-IRES-CreERT2 mice, and adult intestinal tissue examined from tamoxifen-activated Villin-Cre-ERT2 Pten-/- Brafv600E mice. Culture of wild-type embryonic mouse intestine with and without segments removed and / or reversed was performed to investigate the question of what triggers the proximal-to-distal wave of villus morphogenesis. Immunohistochemical interrogation using anti-GFP antibodies was used in the Lgr5- GFP mice to identify the location of Lgr5-expressing cells during the development of villi. Bright-field microscopy, time-lapse in-incubator microscopy, and histological sections assessed villus morphology. The Villin-Cre-ERT2 Pten-/- Brafv600E mouse mutant was explored regarding the intestinal epithelial morphometric changes that occur following tamoxifen-induction. Abstract: Results The proximal-to-distal wave of villus morphogenesis was observed both in vivo and in vitro. Villus morphogenesis commences at embryonic day 14.5 in vivo and after three days in culture from e11.5 in vitro. The villus structures formed in vitro are significantly attenuated compared to in vivo development. An attempt was made to overcome this by providing intestinal explants with a blood supply to aid growth. Evidence is presented that suggest the proximal-to-distal wave of villus morphogenesis is driven by location specific factors intrinsic to each part of the bowel, rather than a domino-like signalling cascade travelling along the intestine. Lgr5-expressing intestinal stem cells were present in early development. Prior to villus morphogenesis they were uniformly distributed along the luminal surface of the intestinal epithelia. During the intense proliferation associated with villus morphogenesis they progressively congregated to the inter-villus spaces. Once villi are fully formed they were absent from the villi but identified in the inter-villus spaces. The Pten/Braf mouse mutant demonstrates villus morphological changes similar to those found following post-bowel resection adaptation. This suggests that there may be a role for Pten/Braf in the epithelial proliferation following extensive bowel resection. Signalling factors in these pathways may be candidate intestinotrophic agents for the treatment of short bowel syndrome. Abstract: Conclusions Before any processes that manipulate intestinal epithelia can be safely translated into therapies to aid adaptation in patients with intestinal failure, it is important to have a full and detailed understanding of the basic science principles that underpin the behaviour of the epithelial cells, both during development and in adulthood. I have explored and quantified the process of villus morphogenesis in the embryonic mouse, investigated the timing of appearance of Lgr5 intestinal stem cells, and interrogated a genetic mouse model with morphometric changes similar to those seen following small bowel resection. I propose two candidate intestinotrophic agents that may hold regenerative potential to augment post small bowel resection adaptation. The next stage of investigation would be to use a mouse model of small bowel resection with manipulation of cell signalling factors to assess impact on post resection adaptation. The ultimate goal would be to investigate epithelial activity in human neonatal intestine and explore methods of modulating this to improve the outcomes from post bowel resection intestinal failure.
5

Manipulating growth and differentiation of embryonic intestine in organ culture

Coletta, Riccardo January 2017 (has links)
Background: An ex vivo experimental strategy replicating in vivo intestinal development would provide an accessible setting to study normal and dysmorphic biology, and would be a test bed for tissue engineering. Previous studies implicated transforming growth factor β1 (TGFβ1) in postnatal gut maturation and regeneration following injury, but its potential role in intestinal development is poorly understood. I firstly hypothesised that embryonic small intestine is able to heal after physical injury. To test this idea, I aimed to create an organ culture model using explants of embryonic jejunum. I secondly hypothesised that TGFβ1 affects embryonic small intestine growth and differentiation. Accordingly, I aimed to use the same organ culture model to determine potential effects of exogenous TGFβ1.Methods. Segments of mouse embryonic jejunum were isolated by dissection and placed on semipermeable platforms. They were fed with defined, serum free, media, in some cases supplemented with TGFβ1. Growth, differentiation and healing of explants were characterized and quantified using a battery of techniques that included whole mount imaging, histology, immunostaining and RNA arrays. TGFβ1 was measured in amniotic fluid by enzyme-linked immunosorbent assay. Groups were compared by statistical tests. Results: After three days of culture, jejunal rudiments differentiated from simple tubes into a more complex structures containing smooth muscle surrounding newly formed villi. Pairs of rudiments, linked by a thread, fused and formed a continuous single lumen, as assessed by trajectories of fluorescent dextrans injected into their distal ends. Functional continuity was confirmed by spontaneous waves of peristalsis crossing the point of fusion. In vivo, TGFβ receptors I and II were detected in embryonic longitudinal smooth muscle cells and, in organ culture, exogenous TGFβ1 induced differentiation of longitudinal smooth muscle. Microarray profiling showed that TGFβ1 increased smooth muscle associated transcripts in a dose-dependent manner. TGFβ1 protein was detected in amniotic fluid at a time when the embryonic small intestine was physiologically herniated. Conclusion: Embryonic jejunal segments can fuse to form a single functional organ when aided by a mechanical manipulation. By analogy with the requirement for exogenous TGFβ1 for smooth muscle differentiation in culture, the TGFβ1 protein that I demonstrated to be present in the amniotic fluid may enhance intestinal development when it is physiologically herniated in early gestation. Future studies of embryonic intestinal cultures should add TGFβ1 in the defined media to produce a more faithful model of in vivo muscle differentiation. In future, this model could be used to test whether other growth factors enhance intestinal growth, and so pave the way to novel biological treatments for short bowel syndrome, a devastating disease with a high mortality.
6

Microbiota intestinal de pacientes portadores da Síndrome do Intestino Curto / Intestinal microbiota of patients with Short Bowel Syndrome

Furtado, Eduarda de Castro 01 October 2010 (has links)
Introdução: A Síndrome do Intestino Curto (SIC) é definida como um conjunto de sinais e sintomas conseqüentes de alterações nutricionais e metabólicas secundária a insuficiência intestinal funcional e/ou orgânica, como nos casos de grandes ressecções do intestino delgado. Ressecções intestinais eliminam sítios de colonização, alteram a área de absorção e, o uso freqüente de antibióticos devido a infecções recorrentes, presença de alimentos não digeridos no cólon, trânsito acelerado e diarréia, nestes mesmos pacientes, podem contribuir para a alteração da microbiota intestinal. Objetivo: Caracterizar a microbiota intestinal de pacientes portadores da Síndrome do Intestino Curto atendidos na Unidade Metabólica e do HCFMRP/USP. Casuística e Métodos: Foram recrutados os pacientes portadores de síndrome do intestino curto atendidos na Unidade Metabólica do HCFMRP/USP (uso de terapia nutricional parenteral). Para o grupo controle foram recrutados indivíduos sadios e eutróficos da comunidade e pareados segundo sexo e idade. Foram avaliadas amostras de fezes e exames bioquímicos, estes últimos foram somente dos pacientes. A avaliação do consumo alimentar foi feita por meio do inquérito Diário Alimenta e a avaliação do estado nutricional a partir de medidas antropométricas. Para detecção de cepas patogênicas foram realizados cultivos e testes bioquímicos específicos em meio aeróbio para determinação de espécies da família Enterobacteriaceae. Em cada cepa de E. coli isolada foram aplicados anti-soros para determinação de possível patogenicidade. Metodologia molecular também foi utilizada para determinação do perfil da microbiota intestinal bacteriana: sequenciamento de bibliotecas de DNAr 16S e PCR para detecção de genes característicos de cepas patogênicas de E. coli. Resultados: Verificou-se a presença de subnutrição protéico-calórica no grupo Paciente mesmo com terapia nutricional para recuperação deste estado nutricional. Quanto a microbiota, observou-se maior diversidade de Gram negativas, porém menor quantidade por grama de fezes da família Enterobacteriaceae em pacientes com SIC. Porém a análise molecular mostrou a manutenção na proporção de espécies bacterianas, equivalente a microbiota intestinal saudável. Conclusão: Apesar da subnutrição, retirada maciça do intestino delgado, uso freqüente de antibióticos, depressão do sistema imune, presença de alimentos não digeridos no trato gastrintestinal e transito intestinal acelerado, a relação e proporção entre as espécies bacterianas intestinais permanecem similares à normalidade. / Introduction The short bowel syndrome (SBS) is defined as a set of signs and symptoms resulting from nutritional and metabolic changes after major small bowel resections. Intestinal resections eliminate colonization sites and alter the absorption area. Besides, the frequent use of antibiotics due to recurrent infections, the presence of undigested food remaining in the intestinal tract, rapid transit and diarrhea in these same patients may contribute to the change of intestinal microbiota. Objective: To characterize the intestinal microbiota of patients with short bowel syndrome treated at the Metabolic Unit and HCFMRP / USP. Materials and Methods: We recruited all the patients with short bowel syndrome treated at the Metabolic Unit of HCFMRP / USP (use of parenteral nutrition therapy). The control group was composed by healthy individuals matched by age and sex. Samples of feces and biochemical tests from the patient group were evaluated. The control group had no biochemical tests, only feces samples to be analysed. The nutritional status was evaluated through anthropometric measurements and the assessment of food intake through food diary survey. The pathogenic strains from Enterobacteriaceae were detected by cultivation and specific biochemical tests in aerobic environment. In each strain of isolated E. coli antisera were applied for determination of pathogenicity. PCR analysis was also used to determine the profile of intestinal bacterial microbiota: sequencing libraries of 16S rDNA and PCR for detection of genes characteristic of pathogenic strains of E. coli. Results: Although receiving periodic parenteral nutrition the Patient group had protein-calorie malnutrition. In regards to the microbiota there was greater diversity, but lower concentration of the family Enterobacteriaceae in patients with SBS. However, the molecular analysis showed the a proportion of bacterial species equivalent to the intestinal flora from the control group. Conclusion: Although the protein-calorie malnutrition, massive resection of the small intestine, frequent use of antibiotics, immune system depression, presence of undigested food in the gastrointestinal tract and rapid intestinal transit rate, the ratio and the proportion of the intestinal bacterial species remain similar to normal.
7

Partners upplevelse av att leva med en person som har kort tarm syndrom : En kvalitativ intervjustudie

Johansson, Anna-Carin, Ohlén, Ingela January 2012 (has links)
Short bowel syndrome (SBS) är ett tillstånd som uppkommer hos personer som har förlorat stora segment av tarmen vilket resulterar i malnutrition och de som har mindre än 2 meter tarm är mycket utsatta. Forskningen visar att det är många aspekter av livet som berörs för de personer som drabbats av SBS och det medför en förändrad livssituation för den sjuke personen. Förändringarna påverkar inte bara den som är drabbad utan även familjen, så som en partner. För att öka vårdarens förståelse för dessa partners situation är det viktigt att uppmärksamma och belysa deras upplevelse. Syftet med studien är att belysa partners upplevelse av att leva med någon som har SBS. Sju personer som lever med en partner som har SBS har intervjuats och analyserats utifrån kvalitativ innehållsanalys. I analysen framkom fem kategorier; förändringar i livet, känslor av uppgivenhet, påverkan på relationen, oro och stöd. Resultatet av denna studie visar att det är många aspekter i livet som påverkas av sjukdomen vilket också berör den sjukas partner. Det framkom att partnern fick göra många anpassningar i sitt liv runt den sjukas behov och det var måltider, toalettbesök och ibland parenteral nutrition som fick styra vardagens planering. De kvinnliga deltagarna i studien uttryckte en känsla av ansvar för familjen, men även för sin sjuka partner periodvis och upplevde det mycket påfrestande. Stödet till den sjuka hade varit bra, men deltagarna upplevde en saknad av stöd och information till de som anhörig. / Program: Specialistsjuksköterskeutbildning med inriktning mot distriktssköterska
8

Role of Glucagon-like Peptide-2 and Elemental Formula in Short Bowel Syndrome – Using Neonatal Piglets as an Animal Model

Hua, Zheng Unknown Date
No description available.
9

Microbiota intestinal de pacientes portadores da Síndrome do Intestino Curto / Intestinal microbiota of patients with Short Bowel Syndrome

Eduarda de Castro Furtado 01 October 2010 (has links)
Introdução: A Síndrome do Intestino Curto (SIC) é definida como um conjunto de sinais e sintomas conseqüentes de alterações nutricionais e metabólicas secundária a insuficiência intestinal funcional e/ou orgânica, como nos casos de grandes ressecções do intestino delgado. Ressecções intestinais eliminam sítios de colonização, alteram a área de absorção e, o uso freqüente de antibióticos devido a infecções recorrentes, presença de alimentos não digeridos no cólon, trânsito acelerado e diarréia, nestes mesmos pacientes, podem contribuir para a alteração da microbiota intestinal. Objetivo: Caracterizar a microbiota intestinal de pacientes portadores da Síndrome do Intestino Curto atendidos na Unidade Metabólica e do HCFMRP/USP. Casuística e Métodos: Foram recrutados os pacientes portadores de síndrome do intestino curto atendidos na Unidade Metabólica do HCFMRP/USP (uso de terapia nutricional parenteral). Para o grupo controle foram recrutados indivíduos sadios e eutróficos da comunidade e pareados segundo sexo e idade. Foram avaliadas amostras de fezes e exames bioquímicos, estes últimos foram somente dos pacientes. A avaliação do consumo alimentar foi feita por meio do inquérito Diário Alimenta e a avaliação do estado nutricional a partir de medidas antropométricas. Para detecção de cepas patogênicas foram realizados cultivos e testes bioquímicos específicos em meio aeróbio para determinação de espécies da família Enterobacteriaceae. Em cada cepa de E. coli isolada foram aplicados anti-soros para determinação de possível patogenicidade. Metodologia molecular também foi utilizada para determinação do perfil da microbiota intestinal bacteriana: sequenciamento de bibliotecas de DNAr 16S e PCR para detecção de genes característicos de cepas patogênicas de E. coli. Resultados: Verificou-se a presença de subnutrição protéico-calórica no grupo Paciente mesmo com terapia nutricional para recuperação deste estado nutricional. Quanto a microbiota, observou-se maior diversidade de Gram negativas, porém menor quantidade por grama de fezes da família Enterobacteriaceae em pacientes com SIC. Porém a análise molecular mostrou a manutenção na proporção de espécies bacterianas, equivalente a microbiota intestinal saudável. Conclusão: Apesar da subnutrição, retirada maciça do intestino delgado, uso freqüente de antibióticos, depressão do sistema imune, presença de alimentos não digeridos no trato gastrintestinal e transito intestinal acelerado, a relação e proporção entre as espécies bacterianas intestinais permanecem similares à normalidade. / Introduction The short bowel syndrome (SBS) is defined as a set of signs and symptoms resulting from nutritional and metabolic changes after major small bowel resections. Intestinal resections eliminate colonization sites and alter the absorption area. Besides, the frequent use of antibiotics due to recurrent infections, the presence of undigested food remaining in the intestinal tract, rapid transit and diarrhea in these same patients may contribute to the change of intestinal microbiota. Objective: To characterize the intestinal microbiota of patients with short bowel syndrome treated at the Metabolic Unit and HCFMRP / USP. Materials and Methods: We recruited all the patients with short bowel syndrome treated at the Metabolic Unit of HCFMRP / USP (use of parenteral nutrition therapy). The control group was composed by healthy individuals matched by age and sex. Samples of feces and biochemical tests from the patient group were evaluated. The control group had no biochemical tests, only feces samples to be analysed. The nutritional status was evaluated through anthropometric measurements and the assessment of food intake through food diary survey. The pathogenic strains from Enterobacteriaceae were detected by cultivation and specific biochemical tests in aerobic environment. In each strain of isolated E. coli antisera were applied for determination of pathogenicity. PCR analysis was also used to determine the profile of intestinal bacterial microbiota: sequencing libraries of 16S rDNA and PCR for detection of genes characteristic of pathogenic strains of E. coli. Results: Although receiving periodic parenteral nutrition the Patient group had protein-calorie malnutrition. In regards to the microbiota there was greater diversity, but lower concentration of the family Enterobacteriaceae in patients with SBS. However, the molecular analysis showed the a proportion of bacterial species equivalent to the intestinal flora from the control group. Conclusion: Although the protein-calorie malnutrition, massive resection of the small intestine, frequent use of antibiotics, immune system depression, presence of undigested food in the gastrointestinal tract and rapid intestinal transit rate, the ratio and the proportion of the intestinal bacterial species remain similar to normal.
10

Effects of Probiotics on Intestinal Failure–Associated Liver Disease in Adult Patients Receiving Prolonged Parenteral Support: A Tertiary Care Center Experience

Alomari, Mohammad, Nusairat, Leen, Al Momani, Laith, Chadalavada, Pravallika, Covut, Fahrettin, Olayan, May, Young, Mark, Romero-Marrero, Carlos 01 June 2020 (has links)
Background: It has been hypothesized that dysbiosis plays a significant role in the pathogenesis of intestinal failure–associated liver disease (IFALD). Therefore, we aimed to investigate the effect of probiotics on IFALD in patients receiving parenteral support, namely home parenteral nutrition (HPN) and home intravenous fluids (HIVFs). Methods: We retrospectively reviewed charts of patients with intestinal failure who received HPN or HIVF for >2 weeks at our tertiary center between January 2005 and August 2016. We excluded patients <18 years of age, patients with other causes of liver disease, patients who used probiotics for <30 days, patients with <6 months' follow-up, and those who had long-term antibiotic use (>30 days). Bivariable and multivariable logistic regression analyses were used in this study. Results: A total of 282 patients who received parenteral support were included. Eighty-five percent of our sample received PN. A total of 78 (27.7%) patients used probiotics. The prevalence of IFALD in patients who used probiotics was 35.9% vs 54.4% in patients who did not use probiotics, P =.005. In multivariable analysis, only small-bowel length of 10-90 cm and HPN use showed a significant impact on IFALD, odds ratio (OR) = 4.394 (95% confidence interval [CI], 1.635-11.814; P =.003) and OR = 4.502 (95% CI 1.412-14.351; P =.011), respectively. Conclusion: Our study revealed that the prevalence of IFALD was comparable among the probiotic users and nonusers. Only small bowel length of 1090 cm and HPN use showed a significant impact on IFALD.

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