Congenital central hypoventilation syndrome associated with Hirschsprung's disease: mutation analysis of the RET and endothelin-signaling pathways.

Three cases of congenital central hypoventilation syndrome (CCHS) associated with Hirschsprung's disease (HSCR) were examined with respect to their genomic DNA on the coding region of the receptor tyrosine kinase (RET) and the endothelin-B receptor (EDNRB). No causative mutations for the disease were detected, but one polymorphism was observed in exon 11 of the RET proto-oncogene. In cases with CCHS, HSCR occurs with a high incidence, and this disease complex has been described as neurocristopathy due to aberrations in neural crest cell proliferation, differentiation or migration during the early fetal period. Both the RET and EDNRB may play important roles in the modulation of neurocristopathies; however, further systemic studies in a large population of patients and control subjects are necessary for elucidating the pathogenesis of this disorder.

Altered immunoreactivity of HPC-1/syntaxin 1A in proliferated nerve fibers in the human aganglionic colon of Hirschsprung's disease.

To clarify the pathogenesis of excessive proliferation of extrinsic nerve fibers in the aganglionic colon of patients with Hirschsprung's disease (HD), we immunohistochemically determined the role that exocytosis-related proteins play in the regulation of exocytosis using the antibody to HPC-1/syntaxin 1A, an exocytosis-related protein. Localization of exocytosis-related proteins (HPC-1/syntaxin 1A, N-ethylmalemide-sensitive fusion protein (NSF), soluble NSF attachment protein (SNAP), synaptotagmin, synaptobrevin, and synaptosome-associated protein 25 (SNAP-25)) was determined in surgical specimens obtained from normal proximal and aganglionic distal segments of the colon of 7 infant patients with HD. In the normal ganglionic colon, Auerbach's plexus, Meisner's plexus, nerve fibers in the muscle layer, and ganglion cells were immunopositive for all six kinds of antisera. In the aganglionic segments, numerous proliferated nerve fibers and hypertrophied nerve bundles were detected in the submucosal layer and myenteric layer by NSF, SNAP, synaptotagmin, synaptobrevin, and SNAP-25. However, HPC-1/syntaxin 1A was not recognized in the proliferated nerve fibers of the submucosal layer or the hypertrophied nerve bundles of the aganglionic segment. These findings show that immunoreactivity of HPC-1/syntaxin 1A was decreased in the affected bowel segments of patients with HD and may be related to the pathogenesis of extrinsic nerve-fiber proliferation in the aganglionic colon of HD.

Japanese patients with sporadic Hirschsprung: mutation analysis of the receptor tyrosine kinase proto-oncogene, endothelin-B receptor, endothelin-3, glial cell line-derived neurotrophic factor and neurturin genes: a comparison with similar studies.

UNLABELLED: We report on mutation analysis of five genes involved in the receptor tyrosine kinase (RET) or the endothelin-signalling pathways in 28 sporadic Japanese patients with Hirschsprung disease. Analysis of DNA obtained from peripheral blood cells revealed six mutations in the RET proto-oncogene, four of which were disease-causing mutations in exon 9 (D584G), the splice donor site of intron 10 (+2T to A), exon 11 (A654T), and exon 12 (T706A). A heterozygous A to G transition was found in 47 bases upstream from the 5' end of exon 2 in two HD patients but was also seen in one control subject (2/28; 1/24). A silent 2307T to G transversion was observed in exon 13. Two disease-causing mutations were detected in the endothelin receptor (EDNRB) gene, in the non-coding region of exon 1 (-26 G to A) and in exon 4 (A301T); the latter mutation was a novel one. One silent mutation was observed in exon 4 (codon 277). One heterozygous T to C mutation was found in the glial cell line-derived neurotrophic factor gene in 25 bases upstream of the coding region in exon 1. No nucleotide changes were detected in either the endothelin-3 or neurturin genes. Disease-causing mutation rates in the RET proto-oncogene and the EDNRB gene were estimated at 14.3% (4/28) and 10.7% (3/28), respectively. In addition to mutations in the RET and EDNRB genes, embryonic environmental factors and/or other genetic factors appear to be involved in the development of Hirschsprung disease. Further systematic studies of genetic variation in a large series of patients and controls are necessary for elucidating the pathogenesis of this disorder. CONCLUSION: This study provides further gene alterations as disease-causing mutations in Japanese cases of sporadic Hirschsprung disease. However, the low mutation rate of the susceptibility genes may indicate that Hirschsprung disease arises from a combination of genetic and environmental factors.

Changing profile of abdominal wall defects in Japan: results of a national survey.

BACKGROUND/PURPOSE: The incidence of gastroschisis has increased over the past 3 decades in a number of countries. To elucidate the Japanese status of anterior abdominal wall defects, the Japanese Society of Pediatric Surgeons conducted a national survey in Japan. METHODS: Information was obtained by sending out a questionnaire to 192 University Hospitals, Children's hospitals, and general hospitals that each had more than 200 beds. The characteristics of the patients including the birth date, birth weight, gestations, rate of associated anomalies, rate of antenatal diagnosis and prognosis, maternal age, gravidity, history of smoking, and drug use were analyzed. RESULTS: The authors obtained answers from 149 institutions, including 1,785 cases of omphalocele and 970 cases of gastroschisis, which were treated between 1975 to 1997. There was a significant increase in the incidence of gastroschisis, from 0.131 in 1975 to 1980, 0.269 in 1981 to 1985, 0.337 in 1986 to 1990, 0.461 in 1991 to 1995 to 0.467 per 10,000 births in 1996 to 1997. The incidence of omphalocele was 0.322 in 1975 to 1980, 0.567 in 1981 to 1985, 0.657 in 1986 to 1990, 0.741 in 1991 to 1995 to 0.626 per 10,000 births in 1996 to 1997, respectively. In the omphalocele group, 43.1% of the mothers were between 25 to 29 years of age, whereas in the gastroschisis group 42.6% of the mothers were 20 to 24 years of age. In the gastroschisis group, the number of primipara mothers was larger than that of multipara mothers. In the omphalocele group, approximately 10% of the mothers smoked during each period, whereas in the gastroschisis group, the percentage of smoking mothers increased chronologically from 12.9% in 1981 to 1985, 18.7% in 1986 to 1990, 23.5% in 1991 to 1995 and 29.3% in 1996 to 1997. A history of drug use by the mother was approximately 10% for both the omphalocele and gastroschisis groups. In the omphalocele group, 55.9% had associated anomalies against 21.8% in the gastroschisis group. Approximately 10% in the omphalocele group and less than 3% in the gastroschisis group showed chromosomal abnormalities. From 1986, a significant number of cases detected antenatally has been observed. CONCLUSIONS: There have been substantial changes in the incidence of anterior abdominal wall defects, particularly regarding gastroschisis in Japan. The reasons for such changes are most likely multifactorial, further epidemiological monitoring is thus called for.

Point nucleotidic changes in both the RET proto-oncogene and the endothelin-B receptor gene in a Hirschsprung disease patient associated with Down syndrome.

A short-segment Hirschsprung disease (HSCR) patient associated with 21 trisomy showing point nucleotidic changes in both the receptor tyrosine kinase (RET) proto-oncogene and the endothelin-B receptor (EDNRB) gene is reported. A T to A heterozygous transition at the splicing donor site of the intron 10 in the RET proto-oncogene, and a G to A heterozygous substitution in non-coding region in the exon 1 of the EDNRB gene were observed. The familial analysis with these genes revealed that the origin of the former mutation was de novo and the latter one was maternal. No patient has been reported with two points mutations in different pathogenetically susceptible loci for HSCR. There is genetic evidence that the RET and EDNRB genes may interact in their susceptibility leading to HSCR.

Urachal cyst associated with a suprapubic sinus.

Urachal anomalies are frequent and may exhibit many anatomical variations. We report a case of a urachal cyst that had a sinus tract extending to the lower abdomen just above the pubic symphysis. Histologic examination of the specimens showed a squamous-epithelium-lined sinus tract and a columnar-epithelium-lined cyst, which suggested a developmental disorder. This may be an extremely rare case where the urachal cyst opened into the suprapubic sinus.

Point mutation in exon 12 of the receptor tyrosine kinase proto-oncogene RET in Ondine-Hirschsprung syndrome.

A 5-year-old girl with congenital central hypoventilation syndrome associated with Hirschsprung's disease (Ondine-Hirschsprung syndrome) representing a missense mutation in exon 12 of the receptor tyrosine kinase (RET) proto-oncogene is reported. Using a direct sequencing technique, genomic DNA obtained from the patient's peripheral leukocytes was analyzed for its nucleotide sequences in all 20 exons of the RET proto-oncogene, seven regions of the 1st to the 7th exon of the endothelin-B receptor gene and endothelin 3 gene, including sequences corresponding to proteolytic cleavage sites. The analysis revealed that adenine at the 2116th base in the 12th exon in the RET proto-oncogene was substituted by guanine, supposedly resulting in a mutation of Thr 706 to Ala. No other mutational change was observed in the gene examined in this case. Mutation analysis has not been described previously on the gene in this disease complex. Mutation in this case might impair the maturation of the tyrosine kinase protein and subsequently cause neurocristopathy supposedly originating from the neural crest.

Laparoscopic removal of a large gastric trichobezoar.

A large trichobezoar has been traditionally removed by open surgery, which has entailed an upper abdominal incision. With the advent of laparoscopic surgery, it became feasible to retrieve a foreign body from the stomach without the necessity of a large skin incision in the upper abdomen. A 7-year-old girl presenting with abdominal pain, nausea, and appetite loss was admitted and evaluated. Results of an upper gastrointestinal series showed a large mass in the stomach that extended into the duodenum. Endoscopical removal had been tried twice under general anesthesia and resulted only in the retrieval of the small portion of the trichobezoar in the duodenum; total removal seemed impossible with endoscopic techniques. Laparoscopic removal was then under-taken to avoid the surgical scar in the upper abdomen. The trichobezoar was successfully retrieved through a gastrotomy and removed via a small suprapubic incision. This approach may be the treatment of choice for future cases of trichobezoar when surgery is indicated.

HPC-1/syntaxin-1A activity in the enteric nervous system of developing rat gastrointestinal tract.

The HPC-1/syntaxin-1A antigen was originally identified as a neuron-specific membrane protein in the central nervous system. The presence of HPC-1 antigen in the nervous system of the fetal rat gastrointestinal tract was immunohistochemically demonstrated using the antibody against HPC-1 to clarify the role of this protein in the development of the enteric nervous system. Rat gastrointestinal tract from 14-, 16-, 18-, and 20-day fetuses and adults were immunohistochemically examined for HPC-1 antigen by light microscopy. Acetylcholinesterase (AchE) activity was also examined as a comparison. HPC-1 activity was first detected on 18th day of gestation. AchE activity was first detected at the Auerbach's plexus of the esophagus on the 16th day of gestation. The presence of HPC-1 in the developing rat intestine revealed that the HPC-1 antigen may be a good indicator for expressing the maturation of enteric nervous system in the development of the enteric nervous system.

The role of prenatal diagnosis in congenital diaphragmatic hernia.

Prenatal diagnosis of surgically correctable fetal anomalies is increasing with the improvement of ultrasonographic techniques. In spite of theoretical advantages, the mortality rate in cases of CDH presenting in the early hours of life has remained high. We have experience of two consecutive cases of CDH, diagnosed prenatally. With maternal transport, planned delivery by Cesarean section, immediate resuscitation of the babies after birth, and prompt surgical intervention by pediatric surgeons, the babies were successfully managed even though they had severe hypoplasia of the left lung. Other reported cases of CDH, have died in the neonatal period mainly from associated lethal anomalies and contralateral lung hypoplasia and in spite of prenatal diagnosis and early surgical intervention. Most of these cases belong to group 3 in Ein's classification. Cases belonging to group 3 are virtually impossible to save with current medical techniques. The effects of prenatal diagnosis on the survival rate in CDH have been discouraging in those series which include these types of cases. The advantage of prenatal diagnosis and early surgical intervention are obvious in groups 1 and 2. Our cases show the importance of cooperation between obstetricians, neonatologists and pediatric surgeons in the prenatal and postnatal management of babies with CDH.

Pressure-induced cardiac hypertrophy: changes in Na+,K+-ATPase and glycoside actions in cats.

Effects of myocardial hypertrophy caused by pressure overload on sarcolemmal Na+,K+-ATPase and positive inotropic action of strophanthidin were examined in cats. Partial ligation of the main pulmonary artery for four weeks resulted in right ventricular hypertrophy with no significant changes in left ventricular muscle. Hypertrophy was associated with a reduction in the number of active Na+,K+-ATPase units. Affinity of the remaining enzyme for [3H]ouabain was unchanged. No apparent right or left shift in dose-response curve for the positive inotropic effect of strophanthidin was observed and toxic concentrations of strophanthidin were unchanged; however, the degree of the positive inotropic effect produced by high concentrations of strophanthidin was significantly smaller in hypertrophied muscle. Moreover, decreases in developed tension rather than tachyarrhythmias was the predominant form of toxicity observed in hypertrophied muscle. These results indicate that myocardial hypertrophy reduces the number of active Na+,K+-ATPase units per milligram protein, decreases maximal positive inotropic effect of strophanthidin, and alters the prevailing form of strophanthidin toxicity.

Hirschsprung's disease: catecholamine content, alpha-adrenoceptors, and the effect of electrical stimulation in aganglionic colon.

In order to assess abnormalities in the adrenergic mechanism in the intestine of Hirschsprung's disease, catecholamine concentrations, alpha-adrenoceptors, and the effect of electrical field stimulation were examined in aganglionic segments of colon or rectum. The aganglionic segment had a higher concentration of norepinephrine, assayed with high performance liquid chromatography with an electrochemical detector, whereas concentrations of epinephrine or dopamine were similar in normal and pathological segments. In four patients with extensive aganglionosis, the norepinephrine concentration in aganglionic colon segments decreased progressively in descending, transverse, and ascending colon. The tissue content of alpha-adrenoceptors and their affinity assayed from the specific binding of [3H]dihydro-alpha-ergocryptine appeared similar in normal and aganglionic segments of the rectosigmoidal colon. Electrical field stimulation of normal rectosigmoidal colon segments caused relaxation at low frequencies and contraction at a very high frequency. Relaxation was not abolished by blocking concentrations of propranolol or phentolamine. In aganglionic segments, the predominant response to electrical field stimulation was contraction, which was inhibited by either atropine or tetrodotoxin. These results indicate that an alpha-adrenergic system and cholinergic innervation apparently exist in aganglionic colon segments and that dysfunction of the colon appears to result from lack of a nonadrenergic inhibitory system.

In ability of Na+,K+-ATPase inhibitor to cause hypertension in sodium-loaded or deoxycorticosterone-treated one kidney rats.

The role of an endogenous inhibitor of Na+,K+-ATPase in hypertension observed in one-kidney NaCl-loaded rats treated with deoxycorticosterone (DOC) was examined. Ouabain or digitoxin, an exogenous inhibitor of Na+,K+-ATPase, failed to cause hypertension in one-kidney NaCl-loaded rats without DOC treatment or one-kidney DOC-treated rats without NaCl loading. Moreover, neither ouabain nor digitoxin acted additively with a putative endogenous inhibitor of Na+,K+-ATPase to augment hypertension observed in one-kidney NaCl-loaded rats treated with DOC. The results do not support the hypothesis that an endogenous inhibitor of Na+,K+-ATPase plays an important role in the development or maintenance of hypertension in this animal model.

Extended dissection of the portahepatis and creation of an intussuscepted ileocolic conduit for biliary atresia.

This paper introduces a new operation for biliary atresia that establishes successful biliary drainage by extending the portahepatic dissection, and decreases ascending cholangitis by incorporating a nonrefluxing intussuscepted draining conduit. An analysis of the postoperative results is presented. The usual dissection of the portahepatis is extended to include the area between and beneath the branches of the right portal vein to incorporate all potentially usable remnants of the intrahepatic ducts. Ascending cholangitis is decreased by interposing an intussuscepted ileocolic segment between the portahepatis and the abdominal wall. This extended dissection of the portahepatis was performed since 1978 in 15 infants with noncorrectable biliary atresia, and bile drainage was achieved in all. In ten infants an intussuscepted ileocolic conduit was constructed. Ascending cholangitis in these ten infants has been either completely absent or easily controlled by antibiotics. The draining bile was highly concentrated due to the water-absorbing capacity of the interposed colonic segment; therefore, fluid and electrolyte disturbances, which develop frequently in patients having jejunal conduits, have never been encountered.