Takashi Shimotake

Congenital choledochal dilatation with emphasis on pathophysiology of the biliary tract

Of 37 patients with congenital choledochal dilatation, aged 8 days to 12 years, who had undergone excision with Roux-en-Y hepaticojejunostomy, 26 patients could be analyzed for morphologic abnormalities and pathophysiology of the biliary tract. Of the 26 patients with congenital choledochal dilatation, 25 (96.2%) had an abnormal choledochopancreaticoductal junction. Of the 12 patients with cystic-type choledochal dilatation, 10 had the C-P type of abnormal choledochopancreaticoductal junction, and of the 13 patients with fusiform-type choledochal dilatation, nine had the P-C type. The amylase levels in the choledochal cyst and the gallbladder were elevated regardless of the form of choledochal dilatation. An adenocarcinoma in a cystic choledochal dilatation was found in one child. Therefore, longstanding inflammation of the biliary tract caused by the reflux of pancreatic juice might be one of the factors in carcinogenesis in the biliary tract. This free reflux of pancreatic juice was demonstrated not only by amylase levels in the biliary tract but also by intraoperative biliary manometry. This reflux might be explained by the lack of sphincter function at the junction of the common bile and pancreatic ducts.

SOX10 mutations in chronic intestinal pseudo-obstruction suggest a complex physiopathological mechanism

Abstract. The type IV Waardenburg syndrome (WS4), also referred to as Shah-Waardenburg syndrome or Waardenburg-Hirschsprung disease, is characterised by the association of Waardenburg features (WS, depigmentation and deafness) and the absence of enteric ganglia in the distal part of the intestine (Hirschsprung disease). Mutations in the EDN3, EDNRB, and SOX10 genes have been reported in this syndrome. Recently, a new SOX10 mutation was observed in a girl with a neural crest disorder without evidence of depigmentation, but with severe constipation due to a chronic intestinal pseudo-obstruction and persistence of enteric ganglia. To refine the nosology of WS, we studied patients with typical WS4 (including Hirschsprung disease) or with WS and intestinal pseudo-obstruction. We found three SOX10 mutations, one EDNRB and one EDN3 mutations in patients presenting with the classical form of WS4, and two SOX10 mutations in patients displaying chronic intestinal pseudo-obstruction and WS features. These results show that chronic intestinal pseudo-obstruction may be a manifestation associated with WS, and indicate that aganglionosis is not the only mechanism underlying the intestinal dysfunction of patients with SOX10 mutations.

Mutational analysis of RET/GDNF/NTN genes in children with total colonic aganglionosis with small bowel involvement.

Hirschsprung disease (HSCR) is characterized by the absence of intramural ganglion cells in the distal gut, resulting in bowel obstruction shortly after birth. Aganglionosis usually affects the distal colon, but may also extensively involve the entire colon and, rarely, the more proximal bowel. Recently, germline mutations of RET, GDNF, and NTN genes have been reported in HSCR. Here we describe the results of mutational analysis of these genes in 15 Japanese child patients with total colonic aganglionosis with small bowel involvement. DNA sequences of all the RET/GDNF/NTN coding regions were determined by the direct dyedeoxy terminator cycle method. Eight different RET mutations were identified in exons 1, 7, 10, 12, 15, and 17 in 10 of the 15 patients. Of these eight mutations, five were found in the tyrosine kinase domain. No GDNF or NTN mutation was found. Compared with typical HSCR, this patient group appeared to exhibit a higher percentage of RET mutations and accumulation of mutations in the tyrosine kinase domain. A homozygous (or hemizygous) RET mutation was found in a male baby with total intestinal aganglionosis, while the heterozygosity of the same mutation resulted in a less severe type of aganglionosis. In familial cases, all heterozygous for the same mutation, aganglionosis was more severe in male than in female siblings. These results also urge us to examine if the RET germline mutation may cause critical alteration of the GDNF/NTN-Ret signal transduction more severely in homo(hemi)zygosity and in male fetuses during organogenesis.

Ultrasonographic detection of intrauterine intussusception resulting in ileal atresia complicated by meconium peritonitis

Abstract A neonate with ileal atresia (IA) complicated by meconium peritonitis (MP) whose prenatal ultrasonography (US) detected an intrauterine intussusception (IUI) is reported. Fetal ascites, dilated bowel loops, and abdominal calcifications were identified on serial US from 25 weeks of gestation. Intestinal loops with high echogenecity and a “target-like” appearance suggestive of IUI were detected in the right lower quadrant. The 2,680-g male was delivered vaginally at term and underwent a laparotomy. Fibrous adhesions and small calcifications were scattered throughout the peritoneal cavity. IA (interrupted type) was confirmed 17.0 cm cranial to the ileocecal valve (ICV). An ileo-ileal intussusception was also found between 16.5 cm and 9.0 cm cranial to the ICV. Partial resection of the ileum and an ileo-ileal anastomosis was performed. The postoperative course was uneventful. In this case, the pathological process of IUI resulting in IA and MP was demonstrated sonographically by identifying the “target-like” appearance in the fetus.

Development of anorectal malformations using etretinate

PURPOSE To investigate the pathogenesis of anorectal malformations (ARM), the authors studied cell proliferation and programmed cell death (apoptosis) patterns in murine embryos that develop ARM as a result of administering an overdose of etretinate, a long-acting vitamin A analogue (retinoid). METHODS Pregnant mice were fed 60 mg/kg of etretinate on the ninth gestational day (E9). Embryos were obtained between E9.5 and E13, and prepared for histological study. Cell proliferation was examined using proliferative cell-specific nuclear antigen (PCNA) expression. Apoptosis was identified by detecting in situ DNA fragmentation using the TdT-mediated dUTP-digoxigenin nick end-labeling (TUNEL) method. RESULTS Over 95% of etretinate-treated embryos had ARM including rectoprostatic urethral or rectocloacal fistula. In the histological study, ARM embryos showed defective cell proliferation in the cloacal membrane and excessive apoptosis in the dorsocaudal region on E11, which resulted in a lack of apoptosis in the anal orifice and a short tail on E12, respectively. Cells forming the urorectal septum showed the same pattern of cell proliferation and apoptosis both in ARM embryos and the controls. These results suggest that impairments of embryonal cellular dynamics in the cloacal membrane and dorsocaudal region induce some types of ARM.

Familial occurrence of intestinal obstruction in children with the syndrome of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS)

The syndrome of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is an uncommon neuromuscular disorder caused by mitochondrial dysfunctions that result in headaches, seizures, and progressive dementia. The authors describe a clinical case study of gastrointestinal manifestations in a pedigree with MELAS, in which all three children, ages 11, 8, and 6, demonstrated acute onset of intestinal obstruction. They unexpectedly showed severe abdominal distension and vomiting. Their parents had no clinical manifestation. The first female sibling underwent an emergent laparotomy because she was diagnosed to have intestinal strangulation. She had postoperative complications caused by progressive lactic acidosis and died the next day. The second and third sisters had similar onsets of the disease and were treated with gastrointestinal decompression and intravenous administration of lactate-free fluid and coenzyme Q10. Genetic testing using blood samples showed an A-to-G point mutation at nucleotide position 3243 in the tRNALeu(UUR) region in the mitochondrial DNA. In MELAS children who demonstrate acute onset of gastrointestinal manifestations, a careful review of family history and an elevation of serum lactate and pyruvate levels may enable a differential diagnosis to be made of acute abdomen to avoid unnecessary surgical intervention.

Mutational analysis of the RET proto-oncogene in a kindred with multiple endocrine neoplasia type 2A and Hirschsprung's disease

BACKGROUND/PURPOSE Germline mutations of the RET proto-oncogene (RET; 10q11.2) have been reported in multiple endocrine neoplasia type 2A (MEN 2A) and Hirschsprungs disease. The authors investigated a Japanese kindred in which MEN 2A and Hirschsprungs disease frequently have been found. METHODS The pedigree consisted of 28 members (11 boys and 17 girls) spanning 4 generations, of whom, 8 were affected with MEN 2A or Hirschsprungs disease. RESULTS Direct sequence DNA analysis of the RET proto-oncogene showed a heterozygosity for a G to C transition at the second nucleotide of codon 620 (exon 10) in the patients, resulting in the replacement of cysteine by a serine residue in the affected Ret protein. This family added a novel RET missense mutation (C620S) predisposing to the association of MEN 2A and Hirschsprungs disease. CONCLUSION Detection of the mutated RET gene carriers may be used for genetic counseling of potential risk for Hirschsprungs disease as well as MEN 2A in the affected families.

A homozygous missense mutation in the tyrosine kinase domain of the RET proto-oncogene in an infant with total intestinal aganglionosis

Germline mutations of the RET proto-oncogene (RET), its ligand glial cell–derived neurotrophic factor (GDNF), and neurturin (NTN) gene have been reported in patients with Hirschsprungs disease. A targeted mutation in the tyrosine kinase domain of RET produced total intestinal aganglionosis and renal agenesis in homozygous transgenic mice. Here we describe a homozygous mutation of the human gene for the RET tyrosine kinase domain that was present in a male neonate with total intestinal aganglionosis. Gut wall biopsy specimens from the stomach to the anorectum showed no ganglion cells. No urinary tract abnormalities were detected. Genomic DNAs were isolated from peripheral blood lymphocytes of the infant and his parents. DNA sequences of all the RET/GDNF/NTN coding regions were determined using a direct DyeDeoxy Terminator Cycle method. A homozygous missense mutation (CGG-to-TGG) at RET codon 969 was identified in this patient, which resulted in an amino acid change from arginine to tryptophan. No germline RET/GDNF/NTN mutations were found in his parents. In this case, the homozygous RET mutation seemed to cause a critical alteration of the Ret tyrosine kinase activity, which resulted in total intestinal aganglionosis but not renal agenesis. Discrepancies in phenotypic expression between humans and mice suggest differing threshold values for RET signal transduction in species or organs.

Biofeedback therapy for fecal incontinence after surgery for anorectal malformations: Preliminary results

Eight patients with fecal incontinence after surgery for anorectal malformations received one to four sessions of biofeedback therapy. The physiologic status of the anorectum before and after biofeedback therapy was investigated by anorectal manometry and electromyography of the external sphincter. The effectiveness of biofeedback treatment and the indications for its use in patients with fecal incontinence were investigated. Three of the four patients responded well to biofeedback therapy following three or four training sessions. However, in the other five patients who had only one or two sessions, a good response to the therapy was not obtained. Anorectal manometry and electromyography recordings of the external sphincter showed that biofeedback therapy improved voluntary sphincter function. The three good responders had an adequate and resting pressure both before and after biofeedback therapy and had good electrical activity of the external sphincter after therapy. In the presence of adequate resting and pressure, biofeedback therapy should be attempted for the treatment of fecal incontinence after correction of anorectal malformations before resorting to further surgical intervention. However, biofeedback therapy may not be suitable if the sphincters are markedly hypoplastic, or do not surround the anal canal after an inappropriate pull-through operation.

Increased numbers of argyrophilic nucleolar organizer regions between primary and metastatic sites predict tumor progression in stage iv and iv-s neuroblastoma

Background. A silver colloid technique to determine nucleolar organizer region (AgNOR) number was used to study the proliferative activity of Stage IV‐S neuroblastoma in which a spontaneous tumor regression is often observed.