Plasticity of the enteric nervous system in patients with intestinal neuronal dysplasia associated with Hirschsprung's disease: a report of three patients

Intestinal neuronal dysplasia is a controversial form of dysganglionosis that has been described both as an isolated disorder and in association with Hirschsprung's disease. It has been blamed for the bad outcome of bowel function in patients operated on for Hirschsprung's disease. According to various authors, intestinal neuronal dysplasia could be a primary disorder or secondary to other diseases of the bowel. The aim of this study was to assess the plasticity of the enteric nervous system in patients with Hirschsprung's disease-associated intestinal neuronal dysplasia and its ability to evolve spontaneously to normal innervation patterns. Since we prospectively introduced the assessment of the enteric nervous system of the ganglionated bowel in patients operated on for Hirschsprung's disease, 31 patients have been operated on for Hirschsprung's disease in our institution between 1995 and 2002. Among these patients, nine suffered postoperatively from severe constipation and five from bouts of entocolitis. IND was found in eight of them. We studied the evolution of the innervation in three of these patients by repeated serial full-thickness biopsies of the colon. All three patients underwent a colostomy before or after the pull-through procedure. Histopathological assessment of the enteric nervous system was made with conventional acetylcholinesterase histochemistry, rapid acetylcholinesterase histochemistry and immunohistochemistry for the Protein Gene Product 9.5 and the antigen CD56. This evolution was compared with the clinical outcome of bowel function. In our three patients with Hirschsprung's disease-associated intestinal neuronal dysplasia, this form of dysganglionosis evolved to normal innervation patterns within a period ranging from 9 to 18months. This evolution was accompanied by an improvement of bowel function in all. We conclude that Hirschsprung's disease-associated intestinal neuronal dysplasia can evolve to a normal innervation, at least under certain circumstances such as a colostomy. Specific histopathological techniques are required to assess accurately the enteric nervous syste

Interstitial cells of Cajal are normally distributed in both ganglionated and aganglionic bowel in Hirschsprung's disease

Surgery for Hirschsprung's disease is often complicated by post-operative bowel motility disorders. The impact of intestinal neural histology on the surgical outcome has been previously studied, but no information is available concerning the influence of the distribution of interstitial cells of Cajal (ICC) on these complications. These cells are considered to be pacemakers in the gastrointestinal tract. The aim of this study was to assess the distribution of ICC in the proximal segment of resected bowel in Hirschsprung's disease and confront these results with the clinical outcome. Using immunohistochemistry for light microscopy, we compared the pattern of distribution of ICC in the proximal segment of resected bowel in Hirschsprung's disease with that in normal colon. We correlated these results with the corresponding neural intestinal histology determined by CD56 and the protein gene product 9.5 immunohistochemistry. The distribution of ICC in the proximal segment of resected bowel is identical to that of normal colon, regardless of normal or abnormal colon innervation. ICC distribution does not seem to contribute to post-operative bowel motility disorders in patients operated for Hirschsprung's diseas

Plasticity of the enteric nervous system in patients with intestinal neuronal dysplasia associated with Hirschsprung's disease: a report of three patients

Intestinal neuronal dysplasia is a controversial form of dysganglionosis that has been described both as an isolated disorder and in association with Hirschsprung's disease. It has been blamed for the bad outcome of bowel function in patients operated on for Hirschsprung's disease. According to various authors, intestinal neuronal dysplasia could be a primary disorder or secondary to other diseases of the bowel. The aim of this study was to assess the plasticity of the enteric nervous system in patients with Hirschsprung's disease-associated intestinal neuronal dysplasia and its ability to evolve spontaneously to normal innervation patterns. Since we prospectively introduced the assessment of the enteric nervous system of the ganglionated bowel in patients operated on for Hirschsprung's disease, 31 patients have been operated on for Hirschsprung's disease in our institution between 1995 and 2002. Among these patients, nine suffered postoperatively from severe constipation and five from bouts of entocolitis. IND was found in eight of them. We studied the evolution of the innervation in three of these patients by repeated serial full-thickness biopsies of the colon. All three patients underwent a colostomy before or after the pull-through procedure. Histopathological assessment of the enteric nervous system was made with conventional acetylcholinesterase histochemistry, rapid acetylcholinesterase histochemistry and immunohistochemistry for the Protein Gene Product 9.5 and the antigen CD56. This evolution was compared with the clinical outcome of bowel function. In our three patients with Hirschsprung's disease-associated intestinal neuronal dysplasia, this form of dysganglionosis evolved to normal innervation patterns within a period ranging from 9 to 18 months. This evolution was accompanied by an improvement of bowel function in all. We conclude that Hirschsprung's disease-associated intestinal neuronal dysplasia can evolve to a normal innervation, at least under certain circumstances such as a colostomy. Specific histopathological techniques are required to assess accurately the enteric nervous system

Simulating glacier lake outburst floods (GLOFs) with a two-phase/layer debris flow model considering fluid-solid flow transitions

Glacier lake outburst floods (GLOFs) initiate with the rapid outburst of a glacier lake, endangering downstream populations, land, and infrastructure. The flow initiates as a mud flow; however, with the entrainment of additional solid material, the flood will often transform into a debris flow. As the run-out slope flattens, the coarse solid material deposits and the flow de-waters. The flow transforms back into a muddy, hyperconcentrated flow of fine sediments in suspension. These flow transitions change the flow composition dramatically and influence both the overall mass balance and flow rheology of the event. In this paper, we apply a two-phase/layer model to simulate flow transitions, solid–fluid phase separations, entrainment, and run-out distances of glacier lake outburst floods. A key feature of the model is the calculation of dilatant actions in the solid–fluid mixture which control flow transitions and phase separations. Given their high initial amount of fluid within the flow, GLOFs are sensitive to slope changes inducing flow transitions, which also implies changes in the flow rheology. The changes in the rheology are computed as a function of the flow composition and do not need any adaptation by ad-hoc selection of friction coefficients. This procedure allows the application of constant rheological input parameters from initiation to run-out. Our goal is to increase the prediction reliability of debris flow modeling. We highlight the problems associated with initial and boundary (entrainment) conditions. We test the new model against the well-known Lake 513 (Peru, 2010), Lake Palcacocha (Peru, 1941), and Lake Uchitel in the Aksay Valley (Kyrgyzstan) GLOF events. We show that flow transition modeling is essential when studying areas that have significant variations in slope

Pédiatrie [News in paediatrics]

Every pediatrician will be confronted with newborns oryoung infants with skin lesions in proximity of the vertebral column. It is important not to miss a spinal dysraphism because of the risk of meningeal infection or of the possible presence of a tethered cord. A practical algorithm is presented. Non-accidental injury in young infants and toddlers is not rare but difficult to detect. Bruises and fractures are highly suspicious for non-accidental injury and should trigger specific investigations. Emergency departments and hospitals are switching from hypotonic to isotonic solutions as maintenance infusions of children. They reduce the risk of hyponatremia without increasing that of hypernatremia, and they should be used preferentially in the majority of pediatric clinical settings

Interstitial cells of Cajal are normally distributed in both ganglionated and aganglionic bowel in Hirschsprung's disease

Surgery for Hirschsprung's disease is often complicated by post-operative bowel motility disorders. The impact of intestinal neural histology on the surgical outcome has been previously studied, but no information is available concerning the influence of the distribution of interstitial cells of Cajal (ICC) on these complications. These cells are considered to be pacemakers in the gastrointestinal tract. The aim of this study was to assess the distribution of ICC in the proximal segment of resected bowel in Hirschsprung's disease and confront these results with the clinical outcome. Using immunohistochemistry for light microscopy, we compared the pattern of distribution of ICC in the proximal segment of resected bowel in Hirschsprung's disease with that in normal colon. We correlated these results with the corresponding neural intestinal histology determined by CD56 and the protein gene product 9.5 immunohistochemistry. The distribution of ICC in the proximal segment of resected bowel is identical to that of normal colon, regardless of normal or abnormal colon innervation. ICC distribution does not seem to contribute to post-operative bowel motility disorders in patients operated for Hirschsprung's diseas

Assessment of the colon innervation with serial biopsies above the aganglionic zone before the pull-through procedure in Hirschsprung's disease

Different types of colonic dysganglionosis, and in particular intestinal neuronal dysplasia (IND) have been blamed for certain postoperative complications after surgery for Hirschsprung's disease (HD). We prospectively assessed colon innervation above the aganglionic zone (AZ) before proceeding to pull-through (PT) in order to rule-out IND as a cause of those complications. We first used a two-stage procedure (TSP): Full-thickness biopsies were harvested above the AZ and a colostomy was established during a first stage. Biopsies were assessed postoperatively with conventional acetyl-cholinesterase (AChE) histochemistry and immunohistochemistry for protein gene product 9.5 (PGP 9.5) and antigen CD56 (CD56). Biopsies were repeated after 6 months if IND was found. When the innervation was normal, the PT was performed during a second stage. Since having refined a rapid AChE reaction, we now use a single-stage procedure (SSP). Biopsies are harvested above the AZ and assessed intraoperatively with rapid AChE staining, proceeding to PT during the same stage when the innervation is normal. Four patients underwent the TSP; 3 had normal innervation above the AZ and subsequently underwent PT. In 1 patient serial biopsies revealed IND-like dysganglionosis; 9 months later, the innervation was normal in repeat biopsies and PT was undertaken. Eleven patients underwent the SSP. Biopsies were normal in 9 but showed unclassifiable forms of dysganglionosis in 2. As these changes were not typical for IND, all patients underwent PT in the same stage. Both patients had a poor outcome of bowel function that required a colostomy in 1 and daily saline irrigations in the other. IND was found in repeat biopsies made during the colostomy in the 1st patient and markedly hypertrophied nerves in the submucosa as well as ectopic nerve cells in the lamina propria in the proximal border of the pulled-through colon in the other. All 13 other patients have normal bowel function. The assessment of colon innervation above the AZ before proceeding to PT allows safer surgical treatment of HD. Intraoperative AChE staining is reliable, but due to the size and number of the biopsies, IND might be overlooked. Non classifiable dysganglionosis should thus be taken into account in the diagnosis and follow-up of the patients, as it may be clinically significant