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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

Distribution and Chemical Coding of Corticotropin-Releasing Factor-Immunoreactive Neurons in the Guinea Pig Enteric Nervous System

Liu, Sumei, Gao, Na, Hu, Hong Zhen, Wang, Xiyu, Wang, Guo Du, Fang, Xiucai, Gao, Xiang, Xia, Yun, Wood, Jackie D. 01 January 2006 (has links)
Immunofluorescence was used to study immunoreactivity (IR) for corticotropin-releasing factor (CRF) in the guinea pig enteric nervous system. CRF-IR was expressed in both the myenteric and the submucosal plexuses of all regions of the large and small intestine and the myenteric plexus of the stomach. CRF-IR nerve fibers were present in the myenteric and submucosal plexuses, in the circular muscle coat, and surrounding submucosal arterioles. Most of the CRF-IR fibers persisted in the myenteric and submucosal plexuses after 7 days in organotypic culture. CRF-IR was not coexpressed with tyrosine hydroxylase-IR or calcitonin gene-related peptide-IR fibers. The proportions of CRF-IR cell bodies in the myenteric plexus increased progressively from the stomach (0.6%) to the distal colon (2.8%). Most of the CRF-IR myenteric neurons (95%) had uniaxonal morphology; the remainder had Dogiel type II multipolar morphology. CRF-IR cell bodies in the myenteric plexus of the ileum expressed IR for choline acetyltransferase (56.9%), substance P (55.0%), and nitric oxide synthase (37.9%). CRF-IR never colocalized with IR for calbindin, calretinin, neuropeptide Y, serotonin, or somatostatin in the myenteric plexus. CRF-IR cell bodies were more abundant in the submucosal plexus (29.9-38.0%) than in the myenteric plexus. All CRF-IR neurons in submucosal ganglia expressed vasoactive intestinal peptide-IR and were likely to be secretomotor/vasodilator neurons. CRF-IR neurons did not express IR for the CRF1 receptor. CRF 1-IR was expressed in neuronal neighbors of those with CRF-IR. Collective evidence suggests that VIPergic secretomotor neurons might provide synaptic input to neighboring cholinergic neurons.
2

Expression of Type 1 Corticotropin-Releasing Factor Receptor in the Guinea Pig Enteric Nervous System

Liu, Sumei, Gao, Xiang, Gao, Na, Wang, Xiyu, Fang, Xiucai, Hu, Hong Zhen, Wang, Guo Du, Xia, Yun, Wood, Jackie D. 17 January 2005 (has links)
Reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiological recording, and intraneuronal injection of the neuronal tracer biocytin were integrated in a study of the functional expression of corticotropin-releasing factor (CRF) receptors in the guinea pig enteric nervous system. RT-PCR revealed expression of CRF1 receptor mRNA, but not CRF2, in both myenteric and submucosal plexuses. Immunoreactivity for the CRF1 receptor was distributed widely in the myenteric plexus of the stomach and small and large intestine and in the submucosal plexus of the small and large intestine. CRF1 receptor immunoreactivity was coexpressed with calbindin, choline acetyltransferase, and substance P in the myenteric plexus. In the submucosal plexus, CRF1 receptor immunoreactivity was found in neurons that expressed calbindin, substance P, choline acetyltransferase, or neuropeptide Y. Application of CRF evoked slowly activating depolarizing responses associated with elevated excitability in both myenteric and submucosal neurons. Histological analysis of biocytin-filled neurons revealed that both uniaxonal neurons with S-type electrophysiological behavior and neurons with AH-type electrophysiological behavior and Dogiel II morphology responded to CRF. The CRF-evoked depolarizing responses were suppressed by the CRF1/ CRF2 receptor antagonist astressin and the selective CRF1 receptor antagonist NBI27914 and were unaffected by the selective CRF 2 receptor antagonist antisauvagine-30. The findings support the hypothesis that the CRF1 receptor mediates the excitatory actions of CRF on neurons in the enteric nervous system. Actions on enteric neurons might underlie the neural mechanisms by which stress-related release of CRF in the periphery alters intestinal propulsive motor function, mucosal secretion, and barrier functions.
3

Regulators of airway submucosal glands development and functions

Xie, Weiliang 01 July 2012 (has links)
Tracheobronchial submucosal glands (SMGs) develop from clusters of epithelial progenitor cells basally orientated within the surface airway epithelium called primordial glandular placodes (PGPs). Signal transduction events that coordinate the transitional process from PGPs into fully developed SMGs consisting of intricately branched networks of tubular secretary structures are still poorly understood. Wnt/β-catenin dependent induction of lymphoid enhancing factor-1 (Lef-1) expression in PGP progenitor/stem cells is required for SMG formation and maturation in the airway. In an effort to better understand the regulatory mechanisms that control Lef-1 during airway SMG development, I have studied its transcriptional regulation. I discovered that Sox2 expression is predominantly confined to the surface airway epithelium (SAE) and is repressed as Lef-1 is induced within PGPs. Deletion of Sox2 in polarized primary airway epithelia significantly enhances Lef-1 mRNA expression. Consequently, my hypothesis is that Sox2 functions as a negative regulator of Lef-1 expression in the SAE. I demonstrated that Sox2 modulates the expression of Lef-1 both independent and dependent on Wnt/β-catenin signaling. I discovered that a Sox2-binding site located in the Wnt Responsive Element (WRE) region of the 2.5Kb Lef-1 promoter is required for Sox2-mediated inhibition of β-catenin-dependent Lef-1 promoter transcription. It is important to understand the biology of SMG development because SMGs are the major mucus-producing structures in the proximal airway and are important in regulating the innate immunity of the lung in response to various neural signals. SMG ducts have also been proposed as a potential protective niche for slowly cycling progenitor cells (SCPCs). Hence, aberrant SMG function is thought to aggravate the pathoprogression of lung disease. Cystic fibrosis (CF) is a disease caused by a defect in the gene that encodes a chloride ion channel called cystic fibrosis transmembrane conductance regulator (CFTR). The absence of CFTR in serous cells within SMG ducts contributes to defective airway secretion, which alters the microenvironment within SMGs. I hypothesized that the glandular SCPC niche may be dysfunctional in CF. I reported that the neural peptide, calcitonin gene-related peptide (CGRP) activates CFTR-dependent SMG secretions and that this signaling pathway is hyperactivated in CF human, pig, ferret, and mouse SMGs. CFTR-deficient mice failed to maintain glandular SCPCs following airway injury, suggesting that the glandular SCPC niche may be dysfunctional in CF. CGRP levels increase following airway injury and function as an injury-inducible mitogen that stimulates progenitor cell proliferation. However, components of the receptor for CGRP (RAMP1 and CLR) were expressed in a very small subset of SCPCs, suggesting that CGRP indirectly stimulates SCPC proliferation through paracrine mechanisms. This discovery may have important implications for injury/repair mechanisms in the CF airway.
4

Purinergic neurogenic intestinal mucosal secretion

Hu, Hong-Zhen 22 December 2004 (has links)
No description available.
5

Prevenção da estenose de esôfago após dissecção endoscópica da submucosa: revisão sistemática e metanálise / Prevention of esophageal stricture after endoscopic submucosal dissecton: systematic review and meta-analysis

Oliveira, Joel Fernandez de 07 December 2017 (has links)
Introdução: A dissecção endoscópica submucosa (ESD) de neoplasias superficiais extensas de esôfago pode evoluir com altas taxas de estenose pós operatória, resultando em uma importante piora na qualidade de vida. Diversas terapias estão disponíveis para prevenir essa complicação. Entretanto, até o momento, nenhuma revisão sistemática e metanálise foram realizadas para avaliar esses resultados. Métodos: Uma revisão sistemática e metanálise foram realizadas utilizando as bases de dados eletrônicas Medline, Embase, Cochrane, LILACS, Scopus e CINAHL. Ensaios clínicos e estudos observacionais foram pesquisados de março de 2014 a fevereiro de 2015. Os termos pesquisados foram: endoscopy, ESD, esophageal stenosis, e esophageal stricture. Três estudos retrospectivos e quatro prospectivos (três randomizados) foram selecionados. Um total de 249 pacientes com diagnóstico de neoplasia superficial de esôfago, submetidos a ESD de pelo menos dois terços da circunferência do órgão foram incluídos. Foram selecionados estudos comparando diversas técnicas para prevenir a estenose de esôfago após extensa ESD. Resultados: Foram realizadas diferentes metanálises com ensaios clínicos randomizados (RCT), ensaios clínicos não randomizados (non- RCT) e uma análise global. Nos RCT (três estudos, n=85), a terapia preventiva diminuiu o risco de estenose (diferença de risco = - 0,36, IC 95% - 0,55 a - 0,18, p = 0,0001). Dois estudos (um randomizado e um não randomizado, n = 55) demonstraram que a terapia preventiva diminui o número médio de dilatações (diferença média = - 8,57, IC 95% - 13,88 a - 3,25, p < 0,002). Não houve diferenças significativas em três RCT em relação à taxa de complicações entre pacientes submetidos à terapia preventiva e aqueles não submetidos (diferença de risco = 0,002, IC 95% -0,09 a 0,14, p = 0,68). Conclusão: O uso da terapia preventiva após extensa ESD no esôfago, reduz o risco de estenose e o número de dilatações endoscópicas para resolução da estenose, sem aumentar o número de complicações / Background: Endoscopic submucosal dissection (ESD) of extensive superficial cancers of the esophagus may progress with high rates of postoperative stenosis, resulting in significant decrease in quality of life. Several therapies are performed to prevent this complication. However, they have not yet been compared in a systematic review. Methods: A systematic review of the literature and meta-analysis were performed using the Medline, Embase, Cochrane, LILACS, Scopus, and CINAHL databases. Clinical trials and observational studies were searched from March 2014 to February 2015. Search terms included: endoscopy, endoscopic submucosal dissection, esophageal stenosis, and esophageal stricture. Three retrospective and four prospective (3 randomized) cohort studies were selected. They involved 249 patients with superficial esophageal neoplasia who underwent ESD of at least two-thirds of the circumference. We grouped trials comparing different techniques to prevent esophageal stenosis post-ESD. Results: Were realized different meta-analyses on randomized clinical trials (RCT), non-RCT, and global analysis. In RCT (3 studies, n=85), preventive therapies decreased the risk of stenosis (risk difference = -0.36, 95% CI= -0.55 to -0.18, p = 0.0001). Two studies (1 randomized, 1 non-randomized, n = 55) showed that preventive therapies lowered the average number of endoscopy dilatations (mean difference = -8.57, 95% CI = -13.88 to -3.25, p < 0,002). There were no significant differences in the 3 RCT studies (n=85) with regards to complication rates between patients with preventive therapies and those without (risk difference = 0.02, 95% CI = -0.09 to 0.14, p = 0.68). Conclusion: The use of preventive therapies after extensive ESD of the esophagus reduces the risk of stenosis and the number of endoscopic dilatations for resolution of stenosis without increasing the number of complications
6

Prevenção da estenose de esôfago após dissecção endoscópica da submucosa: revisão sistemática e metanálise / Prevention of esophageal stricture after endoscopic submucosal dissecton: systematic review and meta-analysis

Joel Fernandez de Oliveira 07 December 2017 (has links)
Introdução: A dissecção endoscópica submucosa (ESD) de neoplasias superficiais extensas de esôfago pode evoluir com altas taxas de estenose pós operatória, resultando em uma importante piora na qualidade de vida. Diversas terapias estão disponíveis para prevenir essa complicação. Entretanto, até o momento, nenhuma revisão sistemática e metanálise foram realizadas para avaliar esses resultados. Métodos: Uma revisão sistemática e metanálise foram realizadas utilizando as bases de dados eletrônicas Medline, Embase, Cochrane, LILACS, Scopus e CINAHL. Ensaios clínicos e estudos observacionais foram pesquisados de março de 2014 a fevereiro de 2015. Os termos pesquisados foram: endoscopy, ESD, esophageal stenosis, e esophageal stricture. Três estudos retrospectivos e quatro prospectivos (três randomizados) foram selecionados. Um total de 249 pacientes com diagnóstico de neoplasia superficial de esôfago, submetidos a ESD de pelo menos dois terços da circunferência do órgão foram incluídos. Foram selecionados estudos comparando diversas técnicas para prevenir a estenose de esôfago após extensa ESD. Resultados: Foram realizadas diferentes metanálises com ensaios clínicos randomizados (RCT), ensaios clínicos não randomizados (non- RCT) e uma análise global. Nos RCT (três estudos, n=85), a terapia preventiva diminuiu o risco de estenose (diferença de risco = - 0,36, IC 95% - 0,55 a - 0,18, p = 0,0001). Dois estudos (um randomizado e um não randomizado, n = 55) demonstraram que a terapia preventiva diminui o número médio de dilatações (diferença média = - 8,57, IC 95% - 13,88 a - 3,25, p < 0,002). Não houve diferenças significativas em três RCT em relação à taxa de complicações entre pacientes submetidos à terapia preventiva e aqueles não submetidos (diferença de risco = 0,002, IC 95% -0,09 a 0,14, p = 0,68). Conclusão: O uso da terapia preventiva após extensa ESD no esôfago, reduz o risco de estenose e o número de dilatações endoscópicas para resolução da estenose, sem aumentar o número de complicações / Background: Endoscopic submucosal dissection (ESD) of extensive superficial cancers of the esophagus may progress with high rates of postoperative stenosis, resulting in significant decrease in quality of life. Several therapies are performed to prevent this complication. However, they have not yet been compared in a systematic review. Methods: A systematic review of the literature and meta-analysis were performed using the Medline, Embase, Cochrane, LILACS, Scopus, and CINAHL databases. Clinical trials and observational studies were searched from March 2014 to February 2015. Search terms included: endoscopy, endoscopic submucosal dissection, esophageal stenosis, and esophageal stricture. Three retrospective and four prospective (3 randomized) cohort studies were selected. They involved 249 patients with superficial esophageal neoplasia who underwent ESD of at least two-thirds of the circumference. We grouped trials comparing different techniques to prevent esophageal stenosis post-ESD. Results: Were realized different meta-analyses on randomized clinical trials (RCT), non-RCT, and global analysis. In RCT (3 studies, n=85), preventive therapies decreased the risk of stenosis (risk difference = -0.36, 95% CI= -0.55 to -0.18, p = 0.0001). Two studies (1 randomized, 1 non-randomized, n = 55) showed that preventive therapies lowered the average number of endoscopy dilatations (mean difference = -8.57, 95% CI = -13.88 to -3.25, p < 0,002). There were no significant differences in the 3 RCT studies (n=85) with regards to complication rates between patients with preventive therapies and those without (risk difference = 0.02, 95% CI = -0.09 to 0.14, p = 0.68). Conclusion: The use of preventive therapies after extensive ESD of the esophagus reduces the risk of stenosis and the number of endoscopic dilatations for resolution of stenosis without increasing the number of complications
7

Optimisation de la technique de dissection sous muqueuse à l’aide d’un bistouri à jet d’eau haute-pression pulsée pour le traitement endoscopique des tumeurs superficielles du tube digestif / Endoscopic submucosal dissection optimizations using a water jet system with high pulsed pressure for the endoscopic treatment of superficial tumors in the digestive tract

Pioche, Mathieu 24 September 2015 (has links)
Dans cette thèse, nous avons travaillé sur les différents versants de la technique de dissection sous-muqueuse et les problèmes que pose ce geste quasi chirurgical dans des unités d'endoscopie initialement médicales. Tout d'abord, nous avons travaillé sur la formation à la technique en développant un modèle d'apprentissage sur colon de bovin plus adapté à la situation européenne où les lésions colo-rectales sont les plus fréquentes. Ce modèle de rectum de bovin, simple à trouver et à préparer permet une formation dans des conditions plus proches de la paroi colique humaine que celles offertes par l'estomac de cochon. Un travail à plus grande échelle évaluant les bénéfices d'une aide à l'apprentissage par un logiciel interactif dédié mené sur ce modèle avec 37 étudiants français et japonais est en cours d'analyse et sera publié prochainement. Ensuite, nous avons réfléchi à la stratégie de la procédure pour la rendre plus simple en évaluant précocement la technique du tunnel pour la dissection des lésions œsophagiennes. Cette stratégie permet de maintenir une traction sur les bords lésionnels et nous offrent une sorte de triangulation en élargissant physiquement la zone de travail. Cette stratégie est devenue un standard pour les résections œsophagiennes dans de nombreuses équipes. Enfin, nous avons travaillé conjointement avec la société Nestis® au développement d'un outil permettant d'optimiser la procédure de dissection sous-muqueuse en associant les bénéfices des bistouris bi fonction (injectant et coupant avec le même outil}, de la haute pression pulsée et des solutions macromoléculaires visqueuses. Le système Nestis® permet pour la première fois cette association et a démontré son intérêt en termes de sécurité et de performance par rapport à la méthode classique utilisant l'aiguille et un bistouri électrique conventionnel. Avec cet outil bi fonction, il n'est plus nécessaire de changer d'instrument puisque toutes les étapes de la procédure sont désormais réalisées avec un seul et même outil. D'autres projets sont déjà prévus avec ce matériel pour étudier ses bénéfices et sa sécurité en dissection colique humaine qui est réputée comme la plus difficile compte tenu de la finesse de la paroi. Enfin, ce matériel offre la possibilité d'injecter sous pression des principes actifs qui pourrait dans le futur permettre de prévenir la survenue de sténoses œsophagiennes ou diriger la cicatrisation. Nous avons ainsi travailler avec la pharmacie de l'hôpital Edouard Herriot pour stabiliser la solution macromoléculaires de mélange de glycérol pour permettre son utilisation en pratique quotidienne / First of all, we worked on the training for unexperienced operators by developing a bovine colon model more adapted to the European situation where colo-rectal lesions are the most common. This model of rectum from bovine, easy to find and to prepare allows training in conditions most close to the human colonic wall than those offered by the pig stomach. Furthermore, such models allows to teach the initial skills but avoiding the risk of adverse events for the first procedures in humans. A future work evaluating the benefits of a learning support by a dedicated interactive software on this model with 37 french and Japanese students is now being analyzed and will be reported soon. Then we thought about the strategy of the procedure in order to make it more simple using the tunnel technique to perform ESD for the esophageal lesions. This strategy helps to maintain traction on the edges and offers a sort of triangulation physically expanding the working space. This strategy has become a standard for esophageal resections in many teams and we still work to improve its efficacy. Finally, we worked jointly with Nestis® Company to develop a tool to optimize the submucosal dissection procedure by combining the benefits of the catheters bi function (injecting and cutting with the same tool), but adding high pulsed pressure and capability to inject viscous macromolecular solutions. The Nestis® system allows for the first time this association and demonstrated his interest in terms of security and performance compared with the conventional method using the needle and a conventional electrocautery device. With this bi function tool, it is not necessary to change instrument frequently since all stages of the procedure are now done with a single device. Other projects are already included with this material to explore its benefits and its safety in human colonic dissection that is deemed as the most difficult due to the thinner wall. Finally, this material offers the possibility to inject pressurized active drugs which could be used in the future to prevent the occurrence of esophageal strictures or to direct healing. We also worked with the hospital Edouard Herriot pharmacy to stabilize the solution glycerol mix to allow its use in daily practice in our unit

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