Aganglionic Megacolon Research Articles

Deciphering potential causative factors for undiagnosed Waardenburg syndrome through multi-data integration

BackgroundWaardenburg syndrome (WS) is a rare genetic disorder mainly characterized by hearing loss and pigmentary abnormalities. Currently, seven causative genes have been identified for WS, but clinical genetic testing results show that 38.9% of WS patients remain molecularly unexplained. In this study, we performed multi-data integration analysis through protein-protein interaction and phenotype-similarity to comprehensively decipher the potential causative factors of undiagnosed WS. In addition, we explored the association between genotypes and phenotypes in WS with the manually collected 443 cases from published literature.ResultsWe predicted two possible WS pathogenic genes (KIT, CHD7) through multi-data integration analysis, which were further supported by gene expression profiles in single cells and phenotypes in gene knockout mouse. We also predicted twenty, seven, and five potential WS pathogenic variations in gene PAX3, MITF, and SOX10, respectively. Genotype-phenotype association analysis showed that white forelock and telecanthus were dominantly present in patients with PAX3 variants; skin freckles and premature graying of hair were more frequently observed in cases with MITF variants; while aganglionic megacolon and constipation occurred more often in those with SOX10 variants. Patients with variations of PAX3 and MITF were more likely to have synophrys and broad nasal root. Iris pigmentary abnormality was more common in patients with variations of PAX3 and SOX10. Moreover, we found that patients with variants of SOX10 had a higher risk of suffering from auditory system diseases and nervous system diseases, which were closely associated with the high expression abundance of SOX10 in ear tissues and brain tissues.ConclusionsOur study provides new insights into the potential causative factors of WS and an alternative way to explore clinically undiagnosed cases, which will promote clinical diagnosis and genetic counseling. However, the two potential disease-causing genes (KIT, CHD7) and 32 potential pathogenic variants (PAX3: 20, MITF: 7, SOX10: 5) predicted by multi-data integration in this study are all computational predictions and need to be further verified through experiments in follow-up research.

Hirschsprung's Disease - Review of Clinical Features, Diagnosis and Treatment

Introduction and purpose: Hirschsprung's disease, also known as congenital aganglionic megacolon, is a rare congenital disorder that affects the large intestine. Due to the absence of ganglion cells, the affected segment of the colon becomes narrow and unable to relax. The disease is present from birth but may not always be immediately apparent. In this paper, we will attempt to present the current state of knowledge regarding the diagnosis and treatment of Hirschsprung's disease, based on the analysis of literature available on the PubMed platform.
 Description of the state of knowledge: Hirschsprung's disease (HSCR), also known as congenital aganglionosis of the colon, involves abnormal migration, proliferation, and differentiation of neural crest cells, leading to the absence of autonomic nerve ganglia within the colon. HSCR is associated with mutations in several genes, with RET, GDNF, EDNRB and SOX10 being identified as the main causes of the disease. Mutations in the RET gene are associated with the hereditary form of Hirschsprung's disease. Symptoms of HSCR appear in newborns and may include bilious vomiting, diarrhea associated with enterocolitis, failure to pass meconium within the first 24 hours of life, impaired peristalsis, jaundice, feeding difficulties, and progressive abdominal distension.
 Summary: Diagnosis is typically made based on clinical presentation, imaging studies, and biopsy. Treatment usually involves surgery to remove the affected segment of the colon and reconnect the healthy portions. Although postoperative complications are relatively common, long-term studies suggest that the majority of children with Hirschsprung's disease function well in society.

Overview of Hirschsprung Disease: A Narrative Literature Review

Hirschsprung disease is a congenital malformation resulting from the failure of neural crest cells to migrate into the gastrointestinal tract. The exact cause of this disorder is unknown, but it is suspected that there is an interaction of several factors, including gene mutations and epigenetic mechanisms. This literature review aimed to describe the pathophysiology, clinical symptoms, and treatment of Hirschprung disease. Mild to severe constipation is a common manifestation of Hirschsprung's disease with poor diet, poor weight gain, and progressive abdominal distention. However, diarrhea may be the first sign, as only water can flow around the affected stool. The most serious complication in the neonatal period is Hirschsprung-associated enterocolitis (HAEC), which can occur both preoperatively and postoperatively. Surgery is the definitive treatment in all cases of Hirschsprung's disease, with resection of the aganglionic segment and anastomosis of the bowel proximal to the anus, known as a pull-through procedure. In conclusion, Hirschsprung disease is a congenital aganglionic megacolon or functional obstruction of the large intestine and is caused by multifactorial factors, especially the role of genetic aspects.

Paneth Cell Hyperplasia and Metaplasia in Hirschsprung-associated Enterocolitis in An Aganglionosis Rat Model

BACKGROUND: Many hypotheses regarding the pathophysiology of enterocolitis in aganglionic megacolon or Hirschsprung disease (HSCR) has been proposed. Paneth cells are columnar intestinal epithelial cells that have an important role in maintaining of intestinal homeostasis as a bactericide. Since enterocolitis in HSCR may have association with Paneth cells metaplasia and hyperplasia, current study investigated Paneth cells metaplasia and hyperplasia in the sigmoid colon of HSCR rat model and its products, namely a-defensins and IL-1b, in the sigmoid colon tissues.METHODS: Aganglionosis-induced and control Sprague-Dawley rats were euthanized on Day (D)-7, -14, -17, -19, -21, -23, -25, and -28. Sigmoid colon tissue was isolated at each time point, and degree of enterocolitis as well as Paneth cells metaplasia and hyperplasia were analyzed by Hematoxylin-eosin staining, then protein levels of a-defensins and interleukin (IL)-1b were determined by enzyme-linked immunosorbent assay (ELISA).RESULTS: Enterocolitis scores increased with time. The Paneth cells metaplasia and hyperplasia were observed on D14 until D28 (p<0.01 vs. control group) followed by an increased in the levels of IL-1b. The levels of a-defensins protein expression were initially increased (D7-D14; p<0.01 vs. control group) but then undergo reciprocal changes on D19 until D28 (p<0.01 vs. D7 and D14). Positive correlations between the degree of enterocolitis and Paneth cells number were detected in the sigmoid colon (r=0.42).CONCLUSION: Paneth cells underwent metaplasia and hyperplasia in the sigmoid colon of HSCR rats corresponding to an increase in the degree of enterocolitis, but not followed by an increase in the level of a-defensins as well as IL-1b, suggesting that there is an involvement of Paneth cells in the pathophysiology of enterocolitis due to HSCR.KEYWORDS: Hirschsprung, enterocolitis, defensins; metaplasia, Paneth cell, animal model

Can Infant Dyschezia Be a Suspect of Rectosigmoid Redundancy?

Infant dyschezia is a functional gastrointestinal disorder that occurs in children less than nine months of age. This disorder causes much anxiety among parents who consult different physicians when suspecting major intestinal problems. The aim of this study is to verify whether infant dyschezia involves an anatomic abnormality (redundancy) of the colon. In this retrospective study (48 months) we analyzed all the children younger than 9 months who came to our attention through the suspicion of gastrointestinal abnormality (Hirschsprung’s disease, anorectal malformations, colonic disorders or constipation). They all had a complete medical history, clinical examination and diagnostic tests, such as blood samples, suction rectal biopsy, a study of stool characteristics and, finally, a contrast enema. In cases with infant dyschezia, different colonic sizes and rectosigmoid length were measured, which created a ratio with the diameter of the second lumbar vertebra. These values were compared with those reported in the literature as normal for the age of one year. Of the 24 patients evaluated (mean age 4 months), 9 were excluded for different diagnoses (aganglionic megacolon, hypothyroidism, constipation). The comparison of the ratios obtained in the remaining 15 cases showed a significantly higher rectosigmoid length (redundancy) in children with dyschezia, 18.47 vs. 9.75 (p < 0.001). The rectosigmoid redundancy, a congenital anomaly already reported as a cause of refractory constipation, may be present in children with infant dyschezia.

NR2F1 regulates a Schwann cell precursor-vs-melanocyte cellfate switch in a mouse model of Waardenburg syndrome type IV.

Waardenburg syndrome type 4 (WS4) combines abnormal development of neural crest cell (NCC)-derived melanocytes (causing depigmentation and inner ear dysfunction) and enteric nervous system (causing aganglionic megacolon). The full spectrum of WS4 phenotype is present in Spot mice, in which an insertional mutation close to a silencer element leads to NCC-specific upregulation of the transcription factor-coding gene Nr2f1. These mice were previously found to develop aganglionic megacolon because of NR2F1-induced premature differentiation of enteric neural progenitors into enteric glia. Intriguingly, this prior work also showed that inner ear dysfunction in Spot mutants specifically affects balance but not hearing, consistent with the absence of melanocytes in the vestibule only. Here, we report an analysis of the effect of Nr2f1 upregulation on the development of both inner ear and skin melanocytes, also taking in consideration their origin relative to the dorsolateral and ventral NCC migration pathways. In the trunk, we found that NR2F1 overabundance in Spot NCCs forces dorso-laterally migrating melanoblasts to abnormally adopt a Schwann cell precursor (SCP) fate and conversely prevents ventrally migrating SCPs to normally adopt a melanoblast fate. In the head, Nr2f1 upregulation appears not to be uniform, which might explain why SCP-derived melanocytes do colonize the cochlea while non-SCP-derived melanocytes cannot reach the vestibule. Collectively, these data point to a key role for NR2F1 in the control of SCP-vs-melanocyte fate choice and unveil a new pathogenic mechanism for WS4. Moreover, our data argue against the proposed existence of a transit-amplifying compartment of melanocyte precursors in hair follicles.

An Unusual Presentation of Congenital Megacolon with A Rare Vascular Anomaly: A Case Report

Congenital megacolon also referred to as Hirschsprung’s disease or aganglionic megacolon is characterized by the absence of nerve plexus in the colon, it rarely affects the small intestine. Whereas acquired megacolon is a constant dilatation of the large intestine in the absence of disease but occurs due to various factors such as infections, emotional disturbances, stress, or secondary to inflammatory bowel diseases (IBD) such as ulcerative colitis, Crohn’s disease, and proctocolitis. In the present case, we report here an unusual form of megacolon. The sigmoid colon was significantly enlarged but twisting or volvulus was not detected. The ascending, transverse, and remaining part of descending colon and mesentery appeared normal, The possibility of false rotation of the gut was excluded. Interestingly, the artery supplying the left one-third of the transverse colon and descending colon originated from a branch of the middle colic artery. This anomalous artery was found to form a communication with the trunk of the inferior mesenteric artery, the Arc of Riolan, and gave branches that supplied the descending colon. The left colic artery was absent. The transverse colon showed a stricture between its right 2/3rd and left 1/3rd, confirming with vascular accidents, resulting in anomalous blood supply and aganglionosis. The dilated part of the sigmoid colon was found to be with ganglion cells, while the distal part after the megacolon, lacked ganglion cells in all layers of the sigmoid colon. This case documents a very rare finding which will make the surgeons aware of a newer arterial pattern associated with congenital megacolon. KEYWORDS: Sigmoid colon, Hirschsprung’s disease, Arc of Riolan.

Waardenburg-Shah syndrome rare and challenging case report from Somalia.

Introduction and importanceWaardenburg-Shah disorder could be an uncommon autosomal recessive inherited ailment characterized by aganglionic megacolon with a high mortality rate. Babies born with Waardenburg syndrome may have typical features of hair, skin and eye pigmentary abnormalities, and hearing loss. Here we present a case with typical presentation of Waardenburg Shah syndrome.Case presentationThis is a case of neonatal intestinal obstruction caused by a rare syndrome known as Waardenburg-Shah syndrome, with clinical manifestations of abdominal distension, bilious vomiting, and a history of delayed meconium passage with a family history of variant forms of this syndrome. The patients underwent first laparotomy, which found no atresia.post op colongarphy revealed a narrowed colon. Then reoperated, and a biopsy was taken and opened ileostomy. The pathology result showed gangilion negative. The patient was lost due to uncontrollable sepsis at the age of 2 months.Clinical discussionWaardenurg syndrome is a congenital audito-pigmentary syndrome first described in 1951.Waardenurg syndrome is classified into four types, WS1 to WS4, and they share the common presence of congenital sensoneural hearing loss and pigmentary defects. The diagnosis of WS has major and minor criteria. The definitive management of this disorder involves surgical removal of aganglionic segment of the bowel and connecting functioning gangilioic bowel to the anus.ConclusionShah-Waardenburg syndrome TYPE-4 is a relatively unusual syndrome characterized by a higher prevalence of whole colonic aganglionosis with or without small bowel involvement, resulting in substantial morbidity and mortality in the neonatal age range.

A Case Report on 2 years Child: Hirschprung’s Disease

Introduction: Hirschsprung's disease is the most common cause of large intestinal obstructing in neonates. Hirschsprung's disease is a congenital anomaly caused by migratory failure of neural crest cells leading to abnormal innervations of the bowel .The defect begins in the internal and sphincter and extends proximally for a variable length of gut. Hirschprung's disease is a disorder of the gut caused due to congenital absence of ganglion cells in the sub-mucosal and myenteric plexus of intestine. This disease is also known as megacolon or congenital Aganglionic megacolon. Case presentation: A 2 years old male child, known case of Hirschprung’s disease, was brought to AVBRH for further management. As narrated by the mother, the child was not passing stool since birth. There was no history of abdominal distention, vomiting or fever. The child pass the stool with the help of enema which was given to the child in the morning and evening. Mast. Devansh has past history of NICU stay. In View of not passing stools, USG of abdomen and pelvis done. Endorectal pull through surgery was done on 4/02/2021 under general anesthesia. No any past surgical history. There is a past history of rectal biopsy done in 1 1/2 month of age. Conclusion:The patient was admitted in AVBRH for further management. Then the report mainly focused on surgical management and quality nursing care due to which patient was discharged without any further complication and satisfaction.

Abdominal compartment syndrome in a 10-year-old boy with delayed presentation of congenital aganglionic megacolon

Abdominal compartment syndrome (ACS) involves adverse physiologic consequences arising from the increased intra-abdominal pressure, leading to high mortality. However, this syndrome has been scarcely reported in pediatric emergency settings. We describe a 10-year-old boy with ACS presenting with painful abdominal distension, oliguria, and dyspnea. Despite the absence of known congenital anomalies, he had undergone frequent episodes of constipation since 5 years of age, and had not defecated for recent 2 months. With computed tomography scans showing the entire colorectal distension, his manifestations were considered to have stemmed from congenital aganglionic megacolon, which had gone undetected. This case underlines the needs for considering ACS and consequent surgical decompression in a child with severe abdominal distension.

A case report of Hirschsprung\u2019s disease presenting as sigmoid volvulus and literature review, Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia

BackgroundSigmoid volvulus is an uncommon problem in children and adolescents, and is rarely considered a diagnosis in this group. A high index of suspicion is necessary to reach a diagnosis and avoid morbidity and mortality. Sigmoid volvulus is a rare complication of Hirschsprung’s disease, which has been reported in neonates, children, and adults. Here we report a case of sigmoid volvulus accompanied by undiagnosed Hirschsprung's disease.Case presentationA 9 years old boy who presented with sudden onset of colicky abdominal pain of 4 h duration associated with gross abdominal distension and 2 episodes of non-bilious vomiting. A plain abdominal radiographs showed single hugely dilated bowel loops in the left lower quadrant with single air fluid level. Sigmoid volvulus was considered and rectal tube deflation was done and it was successful. Full thickness rectal biopsy was done and it was consistent with aganglionic megacolon. A primary trans-anal Soave endo-rectal pull through was done 3 weeks later, after biopsy result arrived, which yielded loss of symptoms and regular bowel movement.ConclusionsSigmoid volvulus should be considered in the differential for children presenting with acute onset of abdominal obstruction. It should be known that when its’s diagnosed in children, it is often associated with Hirschsprung's disease. Therefore, a proper diagnostic and treatment algorithm should be followed in order not to miss associated HD and to give optimum care to such patients.

Çocuklarda Hirschsprung Hastalığı Cerrahi Tedavisi Sonuçları: 12 Yıllık Bir Deneyim

Objective: In the treatment of Hirschsprung’s disease, many surgical techniques have been developed and modified including laparotomy, resection of the affected colon segment, and pull-through of the functional bowel segment to the anus. Conventional surgical methods have many early and late postoperative complications, albeit at a reduced rate today. In this study, it was aimed to compare the treatment results of children with Hirschsprung Disease who were operated with single or two-stage techniques in our department. Method: Hospital records of the patients operated for Hirschsprung disease were retrospectively evaluated. Demografic characteristics, findings of physical and rectal examinations, X-rays findings, rectal biopsy results, surgical treatment methods and outcomes were analyzed. Results: Fifty-two children including 41-male (78.8%) and 11-female (21.2%) patients with age ranging from 1-day to 5-year and mean age of 6.8-day in neonates and 6.3-month in others were enrolled in the study. All patients presented with acute or subacute intestinal obstruction. Levels were observed on supine abdominal radiographs in all; transition zone and retention of opaque material were observed on opaque enema or retention radiographs.In patients whose rectal biopsies revealed aganglionic megacolon two staged procedures were performed including initial colostomy followed by definitive procedure of Duhamel with stapler in 30, and Soave in 12, and Swenson in 1 patient. Nine patients were operated with one-stage endorectal pull-through technique. The complication rate in 43 patients with Hirschsprung disease managed by two staged operative procedure was (78.8%), and it was 11.1% in 9 cases that underwent transanal endorectal pullthrough procedure. It was learned that effective anal dilatation was not performed in 22-patients who had postoperative enterocolitis attacks. Conclusion: In addition to the low complication rate, the morbidity rates in the transanal endorectal pull-through method, which achieved successful results with only one procedure, were very low compared to multiple-stage operations.

Paediatrician’s Suspicion and Radiologist’s Precision in Diagnosing Hirschprung’s Disease in a Child: Case Report

Hirschprung’s disease (HD) is also called as aganglionic megacolon. The entity falls in the group of congenital motor disorders. The usual presentation is in the form of not passing of meconium, abdominal distension with or without vomiting. We present a 2-years old child who was brought with complaints of constipation and difficulty in passing stool. The child was evaluated radiologically by plain radiography, ultrasonography (USG) and barium enema and was diagnosed as a case of short segment type of Hirschsprung disease. The parents had been counselled and advised for pull-through surgery for the child. It is a dilemma for the paediatrician to confirm the diagnosis of Hirschprung’s disease until a radiologically confirmed diagnosis is made. Many cases are delayed for the treatment because of non-diagnosis or delayed diagnosis. The importance lies in the early diagnosis for further surgical management.

Male-biased aganglionic megacolon in the TashT mouse model of Hirschsprung disease involves upregulation of p53 protein activity and Ddx3y gene expression.

Hirschsprung disease (HSCR) is a complex genetic disorder of neural crest development resulting in incomplete formation of the enteric nervous system (ENS). This life-threatening neurocristopathy affects 1/5000 live births, with a currently unexplained male-biased ratio. To address this lack of knowledge, we took advantage of the TashT mutant mouse line, which is the only HSCR model to display a robust male bias. Our prior work revealed that the TashT insertional mutation perturbs a Chr.10 silencer-enriched non-coding region, leading to transcriptional dysregulation of hundreds of genes in neural crest-derived ENS progenitors of both sexes. Here, through sex-stratified transcriptome analyses and targeted overexpression in ENS progenitors, we show that male-biased ENS malformation in TashT embryos is not due to upregulation of Sry-the murine ortholog of a candidate gene for the HSCR male bias in humans-but instead involves upregulation of another Y-linked gene, Ddx3y. This discovery might be clinically relevant since we further found that the DDX3Y protein is also expressed in the ENS of a subset of male HSCR patients. Mechanistically, other data including chromosome conformation captured-based assays and CRISPR/Cas9-mediated deletions suggest that Ddx3y upregulation in male TashT ENS progenitors is due to increased transactivation by p53, which appears especially active in these cells yet without triggering apoptosis. Accordingly, in utero treatment of TashT embryos with the p53 inhibitor pifithrin-α decreased Ddx3y expression and abolished the otherwise more severe ENS defect in TashT males. Our data thus highlight novel pathogenic roles for p53 and DDX3Y during ENS formation in mice, a finding that might help to explain the intriguing male bias of HSCR in humans.

Hirschsprung's Diseases Complicated by Sigmoid Volvulus: A Systematic Review

Hirschsprung's disease and sigmoid volvulus can sometimes be seen in the same patient. To investigate the presence of Hirschsprung's disease in patients with sigmoid volvulus and to discuss the diagnosis and treatment methods. Systematic review. This systematic review has been reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the methodological quality of systematic reviews guidelines. The PubMed and Scopus databases were scanned using the keywords "Hirschsprung* volvulus*" and "congenital aganglionic megacolon volvulus*". The reference list of the selected studies was reviewed for cross-checking. Two reviewers independently screened the available literature. Only the Hirschsprung's disease cases involving sigmoid volvulus were included, and cases of patients with volvulus in other sites was excluded. There was no restriction with respect to the publication language and type of writing. The primary outcome was morbidity and mortality. A total of 31 cases were analyzed in 22 articles; 97% of the patients were under the age of 40, 90% were male. There was a statistically significant difference in the necessity for relaparotomy between patients who were scheduled for sigmoid volvulus therapy with the suspicion of Hirschsprung's disease and patients who were treated without suspicion of Hirschsprung's disease (0% vs 37.5%, p=0.02). While there was no postoperative death in cases with suspected Hirschsprung disease, this mortality rate was 25% in cases without suspicion (p = 0.08). Hirschsprung's disease should be excluded with rectal biopsy if a patient with sigmoid volvulus is under 40 years of age and has complaints of constipation from childhood.

Waardenburg-Shah syndrome (WS type IV): a rare case from Pakistan

Waardenburg-Shah syndrome is a rare autosomal recessive [AR] inherited disorder characterized by the presence of Hirschsprung’s disease with a high likelihood of aganglionic megacolon, due to which the mortality is high. The management of the condition involves surgical intervention for the removal of the aganglionic segment of the colon. Here, we report a neonate that presented with a white forelock, white eyelashes, iris hypopigmentation, and sensorineural deafness associated with bilious vomiting, refusal to feed, and failure to pass meconium indicating intestinal obstruction.

Endothelin-3 gene mutations in isolated and syndromic Hirschsprung disease.

Hirschsprung disease (HSCR, aganglionic megacolon) is a frequent congenital malformation regarded as a multigenic neurocristopathy. Four susceptibility genes have recently been identified in HSCR, namely the RET proto-oncogene, the glial cell line-derived neurotrophic factor (GDNF), the endothelin B receptor (EDNRB) and the endothelin-3 genes (EDN3). Homozygosity for EDN3 mutations has been previously shown to cause the Shah-Waardenburg syndrome, a combination of HSCR with features of the Waardenburg syndrome. Here, we report on heterozygous EDN3 missense mutations in isolatec HSCR. The present data give further support to the role of the endothelin signaling pathway in the development of neural crest-derived enteric neurons. They also suggest the possibility that either recessive or weakly penetrant dominant alleles could occur at the EDN3 locus, depending on the nature of the mutation.

Just Fanciers: Transformative Justice by Way of Fancy Rat Breeding as a Loving Form of Life

A growing trend within feminist animal studies is to eschew the abolitionism/welfarism binary in favor of attending carefully to the politics of existing interspecies relationships in context. This literature maintains that domestication produces special interspecies relationships which generate ongoing responsibilities for human companions and communities. With the goal of clarifying how tending to these ongoing responsibilities to domesticated animals can qualify as enduring forms of interspecies justice, this paper unpacks the politics of these special relationships and obligations in context, specifically, that of fancy rat breeders’ attempts to eliminate aganglionic megacolon. Contrasting fanciers’ efforts with those of laboratory breeders and researchers, I argue that what sets the fancy apart is its shared code of ethics and the loving, principled form of life from which it emerges. Furthermore, the knowledge that rats are worth loving not only enables fanciers to attend to the injustice of megacolon but facilitates transformative justice for domestic rats more broadly.

Gfra1 Underexpression Causes Hirschsprung's Disease and Associated Enterocolitis in Mice.

Background & AimsRET, the receptor for the glial cell line–derived neurotrophic factor (GDNF) family ligands, is the most frequently mutated gene in congenital aganglionic megacolon or Hirschsprung’s disease (HSCR). The leading cause of mortality in HSCR is HSCR-associated enterocolitis (HAEC), which is characterized by altered mucin composition, mucin retention, bacterial adhesion to enterocytes, and epithelial damage, although the order of these events is obscure. In mice, loss of GDNF signaling leads to a severely underdeveloped enteric nervous system and neonatally fatal kidney agenesis, thereby precluding the use of these mice for modeling postnatal HSCR and HAEC. Our aim was to generate a postnatally viable mouse model for HSCR/HAEC and analyze HAEC etiology.MethodsGDNF family receptor alpha-1 (GFRa1) hypomorphic mice were generated by placing a selectable marker gene in the sixth intron of the Gfra1 locus using gene targeting in mouse embryonic stem cells.ResultsWe report that 70%–80% reduction in GDNF co-receptor GFRa1 expression levels in mice results in HSCR and HAEC, leading to death within the first 25 postnatal days. These mice mirror the disease progression and histopathologic findings in children with untreated HSCR/HAEC.ConclusionsIn GFRa1 hypomorphic mice, HAEC proceeds from goblet cell dysplasia, with abnormal mucin production and retention, to epithelial damage. Microbial enterocyte adherence and tissue invasion are late events and therefore unlikely to be the primary cause of HAEC. These results suggest that goblet cells may be a potential target for preventative treatment and that reduced expression of GFRa1 may contribute to HSCR susceptibility.

Digital pathology imaging and computer-aided diagnostics as a novel tool for standardization of evaluation of aganglionic megacolon (Hirschsprung disease) histopathology.

Based on a recently introduced immunohistochemical panel (Bachmann et al. 2015) for aganglionic megacolon (AM), also known as Hirschsprung disease, histopathological diagnosis, we evaluated whether the use of digital pathology and 'machine learning' could help to obtain a reliable diagnosis. Slides were obtained from 31 specimens of 27 patients immunohistochemically stained for MAP2, calretinin, S100β and GLUT1. Slides were digitized by whole slide scanning. We used a Definiens Developer Tissue Studios as software for analysis. We configured necessary parameters in combination with 'machine learning' to identify pathological aberrations. A significant difference between AM- and non-AM-affected tissues was found for calretinin (AM 0.55% vs. non-AM 1.44%) and MAP2 (AM 0.004% vs. non-AM 0.07%) staining measurements and software-based evaluations. In contrast, S100β and GLUT1 staining measurements and software-based evaluations showed no significant differences between AM- and non-AM-affected tissues. However, no difference was found in comparison of suction biopsies with resections. Applying machine learning via an ensemble voting classifier, we achieved an accuracy of 87.5% on the test set. Automated diagnosis of AM by applying digital pathology on immunohistochemical panels was successful for calretinin and MAP2, whereas S100β and GLUT1 were not effective in diagnosis. Our method suggests that software-based approaches are capable of diagnosing AM. Our future challenge will be the improvement of efficiency by reduction of the time-consuming need for large pre-labelled training data. With increasing technical improvement, especially in unsupervised training procedures, this method could be helpful in the future.