Hirschsprung’s disease is a common pathology in pediatric surgery. Besides, long-term outcome of surgically-treated patients remains a crucial issue. The management of Hirschsprung’s disease has remarkably advanced over the years, but difficulties persist particularly in the developing countries (such as Vietnam), where essential diagnostic procedures, such as preoperative histopathological exploration techniques/ facilities (mainly for acetylcholinesterase staining), or adequate postoperative management and follow-up requirements are unavailable.We, therefore, contemplated to work-out a relevant histo-diagnostic approach to overcome these constraints that limit our diagnostic approaches, namely, in Vietnam, and we introduced a “less-demanding” diagnostic approach, namely calretinin immunohistochemical staining which is known to be adequate for formalin-fixed tissues (and thus not necessitating frozen section equipment). We thus used calretinin immunohistochemistry in a prospective study on a large cohort of Vietnamese HD cases. Results showed that rectal suction biopsy using calretinin immunohistochemistry provides an effective histopathological diagnostic tool that can replace AChE and provides a valuable evaluating approach for both preoperative and postoperative management.In addition, we also studied long-term outcome in operated patients and impact of postoperative morbidities on their quality of life. Indeed, a long-term multidisciplinary management with dedicated procedures such as anorectal manometry is essentially required for patients with severe defecation disorders. / Doctorat en Sciences biomédicales et pharmaceutiques (Médecine) / info:eu-repo/semantics/nonPublished

Genetic causes of medullary thyroid carcinoma and Hirschsprung's disease Abstract Medullary thyroid carcinoma (MTC) and Hirschsprung's disease (HSCR) are classified as simple neurocristopathies, i.e. diseases linked to neural crest-derived cells. MTC is derived from parafollicular cells of the thyroid and HSCR is characterized by absence of enteric ganglia in the gastrointestinal tract. The RET proto-oncogene is only expressed in neural crest-derived cells, including parafollicular cells and enteric neurons. The RET encodes a transmembrane tyrosinekinase receptor that plays an important role during proliferation, differentiation and cell survival, and activates many signaling pathways. If the strictly regulated activation fails, e.g. due to mutations in the specific gene locations, the RET becomes a highly effective oncogene. Activating germline mutations in the RET proto- oncogene lead to hereditary forms of MTC, whereas sporadic forms of MTC are caused by somatic mutations in the tumor tissue. On the contrary, inactivating mutations induce migration failure of ganglion cell precursors during the development of enteric nervous system and result in the development of HSCR. In rare cases, the coexistence of both diseases is caused by mutations with a dual gain-of-function and loss-of-function character....

For the purpose of developing an effective therapeutic strategy for HSCR, the enteric neural crest stem cells were investigated firstly which were isolated from the E14.5 mouse embryonic gut, cultured as neurospheres and characterized by multiple immunofluorescence and reverse transcription-PCR, population doubling time, frequency of forming secondary neurospheres and limited dilution assay. In the differentiation culture medium, several types of cells were induced to form from the neurospheres derived from single cells. Hence the putative enteric neural crest stern cells, which were isolated from the embryonic mouse gut tube and cultured as neurospheres for many passages ex vivo with the demonstrated capacity of proliferation, self-renewal and differentiation, showed properties of stem cells. / Hirschsprung's disease (HSCR) is caused by the absence of the enteric neural crest-derived neurons at the distal region of the gut. Cell-based therapy using stem cells or progenitors gives the potential to supplement these missing enteric neurons in the gut. Enteric neural crest stem cells isolated from the human or rodent gut can give rise to neurons and glia after they are transplanted into the recipient guts of the mouse or rat. However, numbers of issues are unresolved about the basic biology of the enteric nervous system, the characteristics of the stem cells isolated from the enteric nervous system and the biological significance of these cells in prenatal and postnatal periods. In this study, the characteristics and therapeutic potential on HSCR of the enteric neural crest stem cells were explored. / In addition to the above, a recombination organotypic gut culture ex vivo showed that the colonization of enteric neural crest-derived cells in the recipient gut was influenced not only by the genotypes of enteric neural crest-derived cells themselves but also the microenvironment of the gut through which enteric neural crest-derived cells migrated. For instance, the developmental stage of the recipient gut and also the presence of endogenous enteric neural crest-derived cells along the migratory pathway of neural crest-derived cells both affected the extent of the migration and colonization of exogenous enteric neural crest-derived cells and stem cells. The gradual maturation and differentiation of the neighboring structures, such as the smooth muscle layer, during the time period of the enteric neural crest cells migration, might also suggest that these neighboring tissues may have a role in regulating the neural crest-derived cells migration. / In conclusion, enteric neural crest stem cells isolated from the embryonic mouse gut tube showed properties of stem cells, and had the potential to compensate missing enteric neural crest-derived cells both ex vivo and in vivo. However, the colonization of enteric neural crest-derived cells in the developing gut was affected cell-autonomously and also by the microenvironment of the gut and the presence of existing enteric neural crest-derived cells. / Their potential applications in the transplantation experiments were shown by transplantation of the neurospheres isolated to the gut tube maintained in an organotypic culture or to the descending colon of neonates at postnatal day 7. The development of the enteric neural crest stern cells from the neurospheres was found to be compatible to endogenous enteric neural crest-derived cells in the recipient gut as evidenced by the formation of interconnected cellular networks of donor stem cells and endogenous neural crest-derived cells. The enteric neural crest stem cells also possess the potential to compensate the loss of enteric neural crest-derived cells ex vivo and in vivo in recipient prenatal and postnatal guts. / Bao, Lihua. / Adviser: Wood Yee Chan. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 208-228). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Introdução: A moléstia de Hirschsprung (MH) se caracteriza pela ausência de neurônios intramurais em segmentos variáveis do intestino grosso, levando a suboclusão intestinal. Na forma mais frequente o reto-sigmoide está comprometido. A biopsia retal é o método histológico de escolha no diagnóstico da MH. O método da hematoxilina e eosina (HE) é classicamente utilizado na prática histopatológica. Nessa técnica, um fragmento de parede total do reto é processado através de parafinização, para posteriormente ser seccionado e corado por HE. Esta coloração evidencia células neurais em intestinos normais e troncos nervosos hipertrofiados nos casos de MH. É uma técnica muito simples, ainda hoje muito utilizada no diagnóstico da doença, necessitando de fragmentos grandes de reto para um maior acerto no diagnóstico. Este detalhe torna o diagnóstico do recém-nascido mais difícil. Outro método de coloração utilizado no diagnóstico da MH é o método histoquímico de pesquisa de atividade de Acetilcolinesterase (AChE). Nesta técnica é necessário apenas um pequeno fragmento de mucosa e submucosa que será congelado e depois processado. A pesquisa de AChE, nos casos de MH mostrará a presença desta enzima em quantidade aumentada, corando troncos e ou fibrilas de cor acastanhado. Este método já vem sendo utilizado pelo Instituto da Criança - HCFMUSP há mais de 30 anos e possui um acerto diagnóstico superior a 90%. Porém, por ser uma técnica mais elaborada, pouquíssimos centros no Brasil a utilizam no diagnóstico da MH. Um outro método mais recente, e que também pode ser realizado em fragmentos menores, é a marcação imunohistoquímica da calretinina, que permite a visualização dos neurônios do plexo submucoso e das fibrilas finas na região da lâmina própria em não doentes. Esta técnica também apresenta maior complexidade e, portanto, não é utilizada. A possibilidade de realizar o diagnóstico da MH através da coloração HE em fragmentos menores poderia ser uma alternativa para os serviços que não dispõe de técnicas mais especificas. Objetivos: Avaliar a concordância dos resultados obtidos pelo método de coloração HE e da calretinina com a pesquisa de atividade de AChE em fragmentos de mucosa e submucosa no diagnóstico da Moléstia de Hirschsprung. Métodos: Para este trabalho foram selecionados 50 casos arquivados em nosso laboratório. O material encontrava-se emblocado em parafina. Foram feitos 60 níveis de cada fragmento para o HE e mais 3 níveis para a calretinina. Essas lâminas foram analisadas em microscópio, fotografadas e classificadas como positivas para MH quando não foram encontradas células neurais e houve a presença de troncos nervosos, e em negativas nos casos de visualização dos neurônios. Foi realizado estudo cego por dois pesquisadores. Os resultados da leitura das lâminas foram comparados com o da AChE. Resultados: Dos 50 casos avaliados pela técnica do HE, apenas 5 discordaram do diagnóstico realizado pela AChE, com um valor de Kappa de 0,800 e acurácia 90%. Na comparação entre a calretinina e a AChE 8 casos discordaram, com um valor de Kappa de 0,676 e acurácia de 84%. Conclusões: A concordância obtida entre os métodos da AChE e HE foi satisfatória. Tornando possível a utilização do método do HE em 60 níveis de fragmento de mucosa e submucosa como alternativa para o diagnóstico da MH. A técnica imunohistoquímica da Calretinina não apresentou a concordância esperada com a pesquisa de atividade de AChE em nosso estudo / Introduction: Hirschsprung disease (HD) is characterized by the absence of intramural neurons in variable segments of the large intestine, leading to intestinal subocclusion. In the most frequent form the rectum-sigmoid is compromised. Rectal biopsy is the histological method of choice in the diagnosis of HD. The hematoxylin and eosin (HE) method is classically used in histopathological practice. In this technique, a full-thickness rectum wall fragment is processed through paraffinization, to be later sectioned and stained by HE. This staining shows neural cells in normal intestines and hypertrophied nerve trunks in cases of HD. It is a very simple technique, still used today in the diagnosis of the disease, requiring large fragments of the rectum for a better diagnosis. This detail makes the diagnosis of the newborn more difficult. The staining histochemical methods more used are the research of acetylcholinesterase activity (AChE) and staining of calretinin. However, these techniques are not available in all centers and the possibility of diagnosing HD through HE staining in smaller fragments could be valuable alternative for services that do not have more specific techniques. Objectives: To evaluate the concordance of the results obtained by the HE staining and the calretinin method with the investigation of AChE activity in fragments of mucosa and submucosa in the diagnosis of Hirschsprung\'s disease. Methods: For this study, 50 cases from our laboratory were selected. The material was embedded in paraffin. Sixty levels of each fragment were made for HE and other 3 levels for calretinin. These slides were analyzed under microscope, photographed and classified as positive for HD when no nerve cells were found and there were nerve trunks present, and in negative in cases of visualization of the neurons. A blind study was carried out by two researchers. The results of reading the slides were compared with that of AChE. Results: Of the 50 cases evaluated by the HE technique, only 5 disagreed with the diagnosis performed by AChE, with a Kappa value of 0.800 and accuracy of 90%. In the comparison between calretinin and AChE, 8 cases disagreed, with a Kappa value of 0.676 and an accuracy of 84%. Conclusions: The concordance of results from AChE and HE methods was satisfactory, allowing the possibility of the use of the HE method in fragments of mucosa and submucosa as valid alternative for the diagnosis of HD. The immunohistochemical technique of Calretinin did not show a good agreement with the AChE activity in our study

Introdução: A moléstia de Hirschsprung (MH) se caracteriza pela ausência de neurônios intramurais em segmentos variáveis do intestino grosso, levando a suboclusão intestinal. Na forma mais frequente o reto-sigmoide está comprometido. A biopsia retal é o método histológico de escolha no diagnóstico da MH. O método da hematoxilina e eosina (HE) é classicamente utilizado na prática histopatológica. Nessa técnica, um fragmento de parede total do reto é processado através de parafinização, para posteriormente ser seccionado e corado por HE. Esta coloração evidencia células neurais em intestinos normais e troncos nervosos hipertrofiados nos casos de MH. É uma técnica muito simples, ainda hoje muito utilizada no diagnóstico da doença, necessitando de fragmentos grandes de reto para um maior acerto no diagnóstico. Este detalhe torna o diagnóstico do recém-nascido mais difícil. Outro método de coloração utilizado no diagnóstico da MH é o método histoquímico de pesquisa de atividade de Acetilcolinesterase (AChE). Nesta técnica é necessário apenas um pequeno fragmento de mucosa e submucosa que será congelado e depois processado. A pesquisa de AChE, nos casos de MH mostrará a presença desta enzima em quantidade aumentada, corando troncos e ou fibrilas de cor acastanhado. Este método já vem sendo utilizado pelo Instituto da Criança - HCFMUSP há mais de 30 anos e possui um acerto diagnóstico superior a 90%. Porém, por ser uma técnica mais elaborada, pouquíssimos centros no Brasil a utilizam no diagnóstico da MH. Um outro método mais recente, e que também pode ser realizado em fragmentos menores, é a marcação imunohistoquímica da calretinina, que permite a visualização dos neurônios do plexo submucoso e das fibrilas finas na região da lâmina própria em não doentes. Esta técnica também apresenta maior complexidade e, portanto, não é utilizada. A possibilidade de realizar o diagnóstico da MH através da coloração HE em fragmentos menores poderia ser uma alternativa para os serviços que não dispõe de técnicas mais especificas. Objetivos: Avaliar a concordância dos resultados obtidos pelo método de coloração HE e da calretinina com a pesquisa de atividade de AChE em fragmentos de mucosa e submucosa no diagnóstico da Moléstia de Hirschsprung. Métodos: Para este trabalho foram selecionados 50 casos arquivados em nosso laboratório. O material encontrava-se emblocado em parafina. Foram feitos 60 níveis de cada fragmento para o HE e mais 3 níveis para a calretinina. Essas lâminas foram analisadas em microscópio, fotografadas e classificadas como positivas para MH quando não foram encontradas células neurais e houve a presença de troncos nervosos, e em negativas nos casos de visualização dos neurônios. Foi realizado estudo cego por dois pesquisadores. Os resultados da leitura das lâminas foram comparados com o da AChE. Resultados: Dos 50 casos avaliados pela técnica do HE, apenas 5 discordaram do diagnóstico realizado pela AChE, com um valor de Kappa de 0,800 e acurácia 90%. Na comparação entre a calretinina e a AChE 8 casos discordaram, com um valor de Kappa de 0,676 e acurácia de 84%. Conclusões: A concordância obtida entre os métodos da AChE e HE foi satisfatória. Tornando possível a utilização do método do HE em 60 níveis de fragmento de mucosa e submucosa como alternativa para o diagnóstico da MH. A técnica imunohistoquímica da Calretinina não apresentou a concordância esperada com a pesquisa de atividade de AChE em nosso estudo / Introduction: Hirschsprung disease (HD) is characterized by the absence of intramural neurons in variable segments of the large intestine, leading to intestinal subocclusion. In the most frequent form the rectum-sigmoid is compromised. Rectal biopsy is the histological method of choice in the diagnosis of HD. The hematoxylin and eosin (HE) method is classically used in histopathological practice. In this technique, a full-thickness rectum wall fragment is processed through paraffinization, to be later sectioned and stained by HE. This staining shows neural cells in normal intestines and hypertrophied nerve trunks in cases of HD. It is a very simple technique, still used today in the diagnosis of the disease, requiring large fragments of the rectum for a better diagnosis. This detail makes the diagnosis of the newborn more difficult. The staining histochemical methods more used are the research of acetylcholinesterase activity (AChE) and staining of calretinin. However, these techniques are not available in all centers and the possibility of diagnosing HD through HE staining in smaller fragments could be valuable alternative for services that do not have more specific techniques. Objectives: To evaluate the concordance of the results obtained by the HE staining and the calretinin method with the investigation of AChE activity in fragments of mucosa and submucosa in the diagnosis of Hirschsprung\'s disease. Methods: For this study, 50 cases from our laboratory were selected. The material was embedded in paraffin. Sixty levels of each fragment were made for HE and other 3 levels for calretinin. These slides were analyzed under microscope, photographed and classified as positive for HD when no nerve cells were found and there were nerve trunks present, and in negative in cases of visualization of the neurons. A blind study was carried out by two researchers. The results of reading the slides were compared with that of AChE. Results: Of the 50 cases evaluated by the HE technique, only 5 disagreed with the diagnosis performed by AChE, with a Kappa value of 0.800 and accuracy of 90%. In the comparison between calretinin and AChE, 8 cases disagreed, with a Kappa value of 0.676 and an accuracy of 84%. Conclusions: The concordance of results from AChE and HE methods was satisfactory, allowing the possibility of the use of the HE method in fragments of mucosa and submucosa as valid alternative for the diagnosis of HD. The immunohistochemical technique of Calretinin did not show a good agreement with the AChE activity in our study

published_or_final_version / abstract / toc / Surgery / Master / Master of Philosophy

Hou, Yonghui. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 174-190). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

Chan, Ka Ki Alex. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 245-263). / Abstracts in English and Chinese. / Abstract --- p.i / Chinese abstract --- p.iii / Acknowledgements --- p.v / Table of contents --- p.vii / Chapter Chapter One --- General introduction --- p.1 / Chapter 1.1 --- Structure and function of the enteric nervous system --- p.1 / Chapter 1.2 --- Neural crest cells (NCC) --- p.5 / Chapter 1.2.1 --- Vagal neural crest cells --- p.7 / Chapter 1.2.2 --- Sacral neural crest cells --- p.10 / Chapter 1.3 --- Prespecialization of the neural crest cells to form ENS --- p.15 / Chapter 1.4 --- Signaling pathways involved in ENS development --- p.19 / Chapter 1.4.1 --- Endothelin signaling pathway --- p.20 / Chapter 1.4.2 --- Ret signaling pathway: GDNF/Ret/GFRa1 --- p.22 / Chapter 1.4.3 --- Ret signaling pathway: NRTN/Ret/GFRa2 --- p.26 / Chapter 1.4.4 --- Phox2b --- p.28 / Chapter 1.4.5 --- Sox10 --- p.29 / Chapter 1.5 --- Hirschsprung's Disease (HSCR) --- p.31 / Chapter 1.6 --- Objective of studies --- p.32 / Figures and legends --- p.35 / Chapter Chapter Two --- The early migratory pathways of mouse sacral neural crest cells --- p.39 / Chapter 2.1 --- Introduction --- p.39 / Chapter 2.2 --- Materials and Methods --- p.46 / Chapter 2.2.1 --- Animals --- p.46 / Chapter 2.2.2 --- Isolation of the mouse embryos at E95 --- p.46 / Chapter 2.2.3 --- Preparation ofWGA-Au --- p.47 / Chapter 2.2.4 --- Preparation of Dil --- p.48 / Chapter 2.2.5 --- Microinjection ofWGA-Au or Dil --- p.48 / Chapter 2.2.6 --- Preparation of rat serum --- p.49 / Chapter 2.2.7 --- Preparation of culture medium --- p.50 / Chapter 2.2.8 --- in vitro whole embryo culture system --- p.50 / Chapter 2.2.9 --- Examination of embryo after culture --- p.51 / Chapter 2.2.10 --- Histological preparation of WGA-Au labelled embryos --- p.51 / Chapter 2.2.11 --- Silver enhancement staining on sections of WGA-Au labelled embryo --- p.52 / Chapter 2.2.12 --- Histological preparation of Dil labelled embryos --- p.53 / Chapter 2.2.13 --- Reconstruction of the mouse embryos --- p.53 / Chapter 2.2.14 --- Cell counting on labelled sacral NCC between the anterior and posterior halves of the somite --- p.54 / Chapter 2.2.15 --- Cell counting on migrating labelled sacral NCC for each somite at different developmental stages --- p.55 / Chapter 2.3 --- Results --- p.57 / Chapter 2.3.1 --- Development of E9.5 mouse embryo in vitro and in vivo --- p.57 / Chapter 2.3.2 --- Labelling of sacral neural crest cells by means of different cell markers --- p.58 / Chapter 2.3.3 --- Migration of sacral neural crest cells at different developmental stages --- p.59 / Chapter 2.3.3.1 --- Distribution of sacral NCC at the 26th somite stage --- p.60 / Chapter 2.3.3.2 --- Distribution of sacral NCC at the 28th somite stage --- p.61 / Chapter 2.3.3.3 --- Distribution of sacral NCC at the 30th somite stage --- p.61 / Chapter 2.3.3.4 --- Distribution of sacral NCC at the 32nd somite stage --- p.63 / Chapter 2.3.3.5 --- Distribution of sacral NCC at the 34th somite stage --- p.64 / Chapter 2.3.4 --- Defined migration pathways of the sacral neural crest cells --- p.65 / Chapter 2.3.5 --- Quantification of migrating sacral NCC at different somite axial levels at different developmental stages --- p.66 / Chapter 2.4 --- Discussion --- p.68 / Chapter 2.4.1 --- E9.5 mouse embryo grew normally in vitro using whole embryo culture --- p.69 / Chapter 2.4.2 --- Migration of sacral neural crest cells at 26th somite stage --- p.70 / Chapter 2.4.3 --- Migration of sacral neural crest cells at 28th somite stage --- p.72 / Chapter 2.4.4 --- Migration or sacral neural crest cells at 30th somite stage --- p.73 / Chapter 2.4.5 --- Migration of sacral neural crest cells at 32nd somite --- p.75 / Chapter 2.4.6 --- Migration of sacral neural crest cells at 34th somite stage --- p.77 / Chapter 2.4.7 --- Majority of sacral neural crest cells migrate along the dorsomedial pathway --- p.80 / Figures and Legends --- p.82 / Tables --- p.136 / Chapter Chapter Three --- The early migratory pathways of Dom mouse sacral neural crest cells --- p.139 / Chapter 3.1 --- Introduction --- p.139 / Chapter 3.2 --- Materials and Methods --- p.145 / Chapter 3.2.1 --- Animals --- p.145 / Chapter 3.2.2 --- In vitro culture of Dom mouse embryos --- p.145 / Chapter 3.2.3 --- Genotyping by polymerase chain reaction (PCR) --- p.146 / Chapter 3.2.4 --- Treatment of the harvested Dom mouse embryos --- p.147 / Chapter 3.2.5 --- Reconstruction of images and cell counting --- p.148 / Chapter 3.2.6 --- Percentage of migrating sacral neural crest cells reduction in Dom mouse embryo --- p.148 / Chapter 3.3 --- Results --- p.150 / Chapter 3.3.1 --- Migration of sacral neural crest cells in Dom mouse embryos at different developmental stages --- p.150 / Chapter 3.3.1.1 --- Distribution of sacral neural crest cells of Dom mouse embryos at the 26th somite stage --- p.150 / Chapter 3.3.1.2 --- Distribution of sacral neural crest cells of Dom mouse embryos at the 28th somite stage --- p.151 / Chapter 3.3.1.3 --- Distribution of sacral neural crest cells of Dom mouse embryos at the 30th somite stage --- p.152 / Chapter 3.3.1.4 --- Distribution of sacral neural crest cells of Dom mouse embryos at the 32nd somite stage --- p.154 / Chapter 3.3.1.5 --- Distribution of sacral neural crest cells of Dom mouse embryos at the 34th somite stage --- p.156 / Chapter 3.3.2 --- Number of migrating sacral NCC of different genotypes of Dom mouse embryos at different developmental stage --- p.158 / Chapter 3.4 --- Discussion --- p.160 / Chapter 3.4.1 --- The use of Dom mouse model to study the etiology of Hirschsprung's disease (HSCR) --- p.161 / Chapter 3.4.2 --- Migration of sacral NCC in Dom mouse embryos --- p.164 / Figures and legends --- p.169 / Tables --- p.230 / Chapter Chapter Four --- General discussion and conclusions --- p.236 / Appendix --- p.241 / References --- p.245