Aims: To study the range of differentiation and presence of cells positive for stem cell markers in 20 sacrococcygeal teratomas (SCTs) which were consecutively operated on between 1990 and 2000 in the Department of Paediatric Surgery in Tübingen, Germany.Methods and results: Preserved paraffin‐embedded material was re‐evaluated. In addition to tissues of various organs, caudal organ structures not described before were identified, such as colon with pancreas originating from colonic crypts, Fallopian tube and vaginal epithelia. The derivation of the latter was confirmed by Müllerian duct specific CA125 and CA19‐9 antibodies. The expression of stem cell markers was studied with antibodies against nanog, Oct4, SSEA‐4, nestin and subtype M3 muscarinic receptors. Cells positive for these markers were encountered in immature end buds and capillary sprouts, and as single cells in neural tissue, gonadal structures, hairs and in the stem cell niches of differentiated epithelia.Conclusions: Our data indicate that SCTs of the newborn arise from remnants of the epiblast‐like tail bud blastema and demonstrate that they contain cells positive for embryonic stem cell markers and may represent a novel source for human embryonic stem cells.

Andreas Flach was an important contributor to German pediatric surgery and, in particular, to pediatric urology. I first met him 1965 when I still was a medical student. He was a surgical senior house officer at the University Hospital of Tübingen. His interest in surgery of children and his surgical talent were already evident but he still intended to gain more experience in neonatal surgery. Therefore he spent some time with Max Grob, former head of the Department of Pediatric Surgery at the University of Zürich.

Introduction: The aim of the study is to establish a complete comprehension of the pathogenesis of Biliary Atresia, and to explain both the variable and redundant pathomorphological, as well as, histological findings. Materials and Methods: The pathomorphological and histological findings in 223 patients with histologically evident EHBA were recorded retrospectively (72 patients) or prospectively (151 patients), according to a projected ascending study. These findings were compared with histological findings in human and rat embryos. Results: 1) The pathomorphological findings recorded in patients with EHBA were also found in stages of normal embryogenesis of the bile duct system in human and rat embryos. 2) Each histological finding in Biliary Atresia corresponds to a finding in an interrupted stage of the normal development in human and rat embryos. 3) The findings in patients and embryos can be explained completely by a disturbed intrinsic epithelium/mesoderm interaction. 4) Some findings in Biliary Atresia cannot be explained easily by the assumption of an extrinsic factor. Conclusion: There is no finding in Biliary Atresia which cannot be completely explained as the result of an intrinsic developmental error, probably due to disturbances or interruption of epithelium/mesoderm interaction during embryogenesis.

BACKGROUND:The aim of this study is to show that five distinct types of tracheal anomalies should be differentiated with respect to therapy and prognosis.METHODS:The records of 12 infants and children seen over a period of 20 years for different tracheal anomalies such as laryngotracheal stenosis (n = 3), long or short-segment stenosis of the upper (n = 2), middle (n = 6), and lower (n = 1) trachea were reviewed. In addition to these 12 patients with congenital stenosis, 3 other patients needed tracheal resections because of oncologic or traumatic disease: in 2, the trachea was infiltrated by a papillary carcinoma of the thyroid gland and in one, the upper part of the trachea was injured by an oral explosion accident. 25 patients presenting during the same period for other tracheal pathologies including esophagotracheal cleft syndrome (n = 7), tracheomalacia (n = 4), total tracheal agenesis (n = 3), or for placement of a tracheostomy (n = 11) due to other diseases were excluded from this study.RESULTS:There was 1 early death after repair of a laryngotracheal stenosis by cricoid-split and cricoid-splint due to both cerebral hemorrhage and cardiac insufficiency secondary to Fallot's tetralogy. Another child died four weeks after slide tracheoplasty as a result of hypoxic cerebral lesions induced by severe central catheter-related septicemia. One child with therapy-resistant obstructing granulation tissue which developed after a slide tracheoplasty required a tracheostomy. The patient with the tracheal injury died after another accident one year after discharge. All other patients (n = 11) are doing well.CONCLUSIONS:With respect to therapy of congenital and post-intubation tracheal stenosis, four types should be distinguished. Each of these types requires an adequate surgical procedure. The most important postoperative problem in tracheal surgery is the development of granulation tissue. However, the pathogenesis of granulation is still unknown.

INTRODUCTION:The pathogenetic model for biliary atresia presently most favored is that EHBA is the result of a peri- or postnatal bile duct lesion. Several authors demonstrated inflammatory infiltrations in the mesenchymal areas of the liver and thus concluded an infectious genesis. An association of rota-, reo- (and CMV) virus infection with EHBA was suspected, but the presence of these viruses in EHBA could not be reproduced. In view of this controversial debate we found it to be indicated to investigate tissue blocks from the porta hepatis and liver biopsies in children with EHBA by histo- and immunohistochemistry for the quality and quantity of leukocyte infiltrations.METHODS:31 tissue excidates of the porta hepatis were gained on the occasion of hepatoportoenterostomy, fixed in 4 % buffered formalin and embedded in paraffin. The presence of leukocyte infiltrations and their subpopulations was demonstrated by histochemical reactions and immunohistochemical staining methods using specific antibodies against surface markers. The number of leukocytes and their subpopulations was counted in three different regions of the porta hepatis, the obliterated extrahepatic bile duct, the fibrous mass of the porta hepatis and the transition zone between the fibrous mass and liver parenchyma. A statistical analysis was done.RESULTS:In EHBA, leukocyte infiltrations consist mainly of macrophages. Antigen-presenting cells and lymphatic cells play a minor role. Lymphatic cells could only be detected in 6 out of 31 tissue preparations. Antigen-presenting cells could only be detected via anti-F13a antibody which shows cross-reactivities, i.e. against macrophages and embryonal tissue. Evaluating the density of leukocyte infiltrations with regard to the different anatomical regions of the porta hepatis we could demonstrate that leukocyte infiltrations are scarce around the rudiment of the bile duct whereas the highest leukocyte density could be found in the fibrous mass of the porta hepatis and the intrahepatic fibrous septs interconnecting the fibrous mass of the porta hepatis with liver parenchyma. Liver parenchyma was mainly free of leukocyte infiltrations with the exception of neutrophilic granulocytes. Regardless of the subpopulations, leukocytes were mainly arranged around the bile ducts of the fibrotic septa.CONCLUSIONS:Most tissue preparations from children operated on during the 4th-8th week of life show only small leukocyte infiltrations and in the majority of cases no immunocompetent lymphocytes. This leads to the conclusion that a virus infection as an underlying cause for EHBA is very unlikely. Most probably, the observed leukocyte infiltrations are due to an unspecific phagocytotic activity. Comparing our results to reports from Hadchouel et al (9) and Landing et al (12) led us to believe that a pathologic immunoreaction with a possible defective antigen elimination could also be considered as a reason for EHBA.

Renal insufficiency developed in a newborn with huge bilateral renal cysts and posterior urethral valves. Definitive therapy consisted of laser coagulation of the valves and transient percutaneous drainage of the cysts.

Genetic aberrations are the primary events leading to carcinogenesis in various tissues and are characteristic for certain tumor types. Amplification of N-myc and deletion of 1p significantly correlate with poor prognosis of neuroblastoma patients. Very little informations is available on the regulation of N-myc expression by external factors. Insulin-like growth factor-II (IGF-II) has been identified as an autocrine growth factor in neuroblastoma. Four neuroblastoma cell lines were examined for their expression of IGF-II and IGF-receptor. Stimulation of neuroblastoma cells with IGF-II leads to an increased activity of the MAP-kinase Erk1, an induction of N-myc expression and an enhanced proliferation rate. In order to disrupt the signal transduction of the IGF-receptor, we inactivated the Ras-proteins in neuroblastoma cells by inhibition of the farnesyl-protein transferase by FTI-277. This inactivation prevented activation of MAP-kinase Erk1 and induction of N-myc expression by IGF-II. Inactivation of Ras by farnesyltransferase inhibitors might become a promising new approach in future treatments of neuroblastoma tumors.

Purpose: We retrospectively evaluatedthe technical and long-term clinical results of transjugularintrahepatic portosystemic shunts (TIPS) in children with portalhypertension and biliary atresia (BA). Methods: Ninechildren with BA and recurrent bleeding from esophagogastric and/orintestinal varices were treated by TIPS at the age of 34–156 monthsand followed-up in two centers. Different types of stents wereused. Results: Shunt insertion succeeded in allpatients, but in two a second procedure was necessary. Seven procedureslasted more than 3 hr, mainly due to difficult portal vein puncture.Variceal bleeding ceased in all patients; however, 16 reinterventionswere performed in eight patients for clinical reasons (n =11) and sonographically suspected restenosis (n =5). Four patients underwent successful liver transplantation 4–51months after TIPS and five are in good clinical conditions 64–75months after TIPS. Conclusions: TIPS in children with BAis technically difficult, mainly due to periportal fibrosis and smallportal veins. Frequency of reinterventions seems to be higher comparedwith adults.

Berichtet wird über ein Neugeborenes mit ausgedehnter arteriovenöser Malformation im Bereich des rechten Armes und massiver cardialer Insuffizienz wegen AV-Shunt im Tumor. Zunächst erschien aufgrund der klinischen Situation eine Amputation des Armes im Rahmen der Extirpation des Gefäßtumors unumgänglich. Wegen Herzinsuffizienz kontrollierte Beatmung, Dopamin-Gabe und Digitalisierung. Durch teilweise Embolisierung der Malformation und komprimierende Verbände gelangt die Stabilisierung unter Erhaltung der Armdurchblutung. Unter lokaler Instillation von Triamcinolon und Dexamethason und anfänglich systemischer Gabe von Corticoiden bildete sich die Gefäßmalformation schrittweise zurück. Nach 20 Monaten sind im wesentlichen noch die oberflächlichen, cutanen Hämangiomanteile zurückgeblieben.

Laser resection (LR) of posterior urethral valves during infancy as early as possible after diagnosis appears to represent a safe and reliable method. In contrast to other procedures, LR allows valve ablation with thin cystoscopes and carries little risk, even in premature and newborn infants. Its application in seven children in the course of 2 years principally confirmed its suitability for use: it could be applied in all cases without any problems and led to extensive resection of the valve tissue and removal of the obstruction in all patients. The encouraging clinical findings were confirmed by control cystoscopies and micturating cystourethrograms. Complications arising from the method were not observed.

Presently only those forms of Extrahepatic Biliary Atresia (EHBA) with minimal or no intrahepatic manifestations can be treated successfully by extensive hepatoportoenterostomy. Intraoperative macro- and microscopic observations show that the typical pathogenetic manifestations in EHBA are most prominent at the porta hepatis. We therefore postulate that EHBA is the result of a defective embryonic development of the porta hepatis. In rat embryos hepatic bile duct formation is initiated at the porta hepatis and in this context mesenchyme from the periportal region seems to play a major inductive role. In order to demonstrate the role of invading periportal mesenchyme for the process of bile duct rudiment formation we established an organ culture model of the embryonic porta hepatis by recombining periportal mesenchyme with peripheral liver fragments from 15 days old rat embryos (Carnegie Stage 21). The degree of mesenchyme invasion as well as the formation of mesenchyme-surrounded liver cell clusters, rosettes or vesicles (bile duct rudiments) were assessed. Mesenchyme from the porta hepatis invaded the peripheral liver fragments and induced the formation of mesenchyme-surrounded liver cell clusters and rosettes with the beginning of lumen formation. Kidney mesenchyme recombined with liver fragments as a mesenchymal alternative showed almost the same effect, lung mesenchyme showed only a very weak inductive effect. To assess the effect of a diffusible factor versus direct cell contact, a millipore filter with and without paraffin coating was interposed between mesenchyme containing tissue and peripheral liver tissue fragments. Without direct cell contact to mesenchyme no hepatoblast cluster or rosette formation could be observed. Comparing this result to the normal development of the liver in rats our investigations suggest that the embryogenesis of the porta hepatis is probably defined by the following two developmental steps: First, differentiation of the intrahepatic bile duct system which is induced by invading mesenchyme originating from the extrahepatic periportal region and realized by epithelium mesenchyme interaction. Second, fusion of extra- and intrahepatic bile duct systems at the level of the later porta hepatis. Disturbances of this complex process can possibly lead to biliary atresia. Further investigations regarding details of the role of the mesenchyme, its inductive factors and the kidney mesenchyme's inductive potential in liver development may provide a new perspective for future treatment of biliary atresia.

Anhand von 2 Patientenkasuistiken möchten wir auf eine wegen des möglichen Kurzdarmes sehr schwerwiegende Variante des Gastroschisis aufmerksam machen. Bei einem Patienten ohne präpartalen Nachweis einer Gastroschisis fand sich nach der Geburt in der 31. SSW ein nekrotischer Darmrest an einer spontan verschlossenen Gastroschisis, der gesamte Dünndarm vom Duodenum bis zum Querkolon fehlte. Bei der zweiten Patientin mit bekannter Gastroschisis erfolgte wegen kindlicher Probleme in der 34. SSW eine Sectio. Hierbei fand sich der prolabierte Dünndarm durchblutungsgestört in einer sich verschließenden Bauchdeckenlücke; er erholte sich nach sofortiger Entlastung. Es wird über die spärlichen Literaturmitteilungen dieser Komplikation berichtet und eine Strategie zur Vermeidung vorgeschlagen.

In neuroblastoma, amplification of the protooncogene N-myc is the most important molecular characteristic predicting a bad outcome for the patients. Despite the importance of the N-myc gene, little is known about the mechanisms regulating its expression. We found evidence that insulin-like growth factor II stimulates the growth of neuroblastoma in a paracrine fashion. Two neuroblastoma cell lines predominantly expressed IGF-II whereas two other cell lines expressed the IGF-receptor. In a receptor-positive cell line, N-myc expression was enhanced by stimulation with IGF-II. As the growth-stimulating signals of the IGF receptor are transmitted via Ras proteins, inactivation of Ras is one promising tool to prevent the induction of N-myc expression by IGF-II. Treatment of neuroblastoma cells with an inhibitor of the farnesyl-protein-transferase (FPTase) inactivated H-ras protein completely and N-ras protein by more than 50 %. Cell growth of neuroblastoma cells in serum containing medium was clearly diminished by inhibition of FPTase. The growth-promoting effect of IGF-II was reduced to exactly half the amount observed in non-inhibited cells.

In neuroblastoma, amplification of the protooncogene N-myc is the most important molecular characteristic predicting a bad outcome for the patients. Despite the importance of the N-myc gene, little is known about the mechanisms regulating its expression. We found evidence that insulin-like growth factor II stimulates the growth of neuroblastoma in a paracrine fashion. Two neuroblastoma cell lines predominantly expressed IGF-II whereas two other cell lines expressed the IGF-receptor. In a receptor-positive cell line, N-myc expression was enhanced by stimulation with IGF-II. As the growth-stimulating signals of the IGF receptor are transmitted via Ras proteins, inactivation of Ras is one promising tool to prevent the induction of N-myc expression by IGF-II. Treatment of neuroblastoma cells with an inhibitor of the farnesyl-protein-transferase (FPTase) inactivated H-ras protein completely and N-ras protein by more than 50 %. Cell growth of neuroblastoma cells in serum containing medium was clearly diminished by inhibition of FPTase. The growth-promoting effect of IGF-II was reduced to exactly half the amount observed in non-inhibited cells.

Bile stones lodged in the ampulla of Vater present a rare but often difficult problem. Considering the disadvantages of conventional papillotomy and papillectomy, we developed a technique in which both the anatomic structures and their function are preserved. Histologic studies of the ampulla provided the basis for the technique, in which the muscular layers of the ampulla are not cut through as in conventional papillotomy but are bluntly separated, preserving this important anatomic component of the ampulla saved. The postoperative and long-term outcome of seven patients with bile stones lodged in the ampulla are reported. We found semicircular lateral papillotomy a safe procedure that preserves the muscular structures and function of the ampulla.

Neuroblastoma is the second-most common solid tumor in childhood. The majority of patients have a very poor outcome due to aggressive growth and metastatic spread. In contrast, in rare cases, spontaneous regression or differentiation towards a benign ganglioneuroma are observed. The mechanism leading to differentiation of neuroblastoma is of particular therapeutic interest. In this paper we report the results of our attempts to induce the expression of genes necessary for differentiation of neuroblastoma cells. TrkA codes for the high affinity receptor of NGF, a neurotrophin known to promote differentiation. Treatment with retinoic acid caused a 3-fold increase of the trkA expression in neuroblastoma cell lines. Neurofibromin, the gene product of the NF-1 gene, is involved in downregulation of the activity of ras-proteins. In contrast to immature neuronal tissues in mature brain, the type II isoform of neurofibromin is predominantly expressed. Retinoic acid was able to raise the proportion of type II NF-1 expressed in neuroblastoma cells.

Questions: How may gallstones develop if there is no hemolytic disorder and no malformation or alteration of the gallbladder and cystic ducts? Was there a change in the incidence of stones and the assignment of the patients to different age groups? The literature gives answers to these questions on the basis of only few cases. Therefore, a relatively large prospective database of collected cases during 30 years shall be used to give additional answers. Methods: The data are derived from 111 children with symptomatic gallstones without hemolytic diseases. 109 of them required operative therapy. They were examined preoperatively and postoperatively maximum during 30 years of follow-up as well according to a defined program. This program includes taking the patient’s history, evaluation of clinical, radiological including sonographical examination, exclusion of hemolytic primary diseases, histological investigation of intraoperatively gained specimens of the gallbladder, and the spectroscopic qualitative as well as semiquantitative analysis of stones and bile. Results: (1) The qualitative and quantitative composition of the stones is different in the four age groups. (2) The causes of lithogenesis are different in the four age groups. (3) Children with long-term TPN, after cardiopulmonary bypass operations, after extended small bowel resection, suffering from obesity, and girls using hormonal contraception are at risk of developing gallstones. We recommend to observe these patients by repeated ultrasound controls for gallstone formation during a minimum of 10 years. (4) Malformations and pathological alterations of the gallbladder are rare causes for increased lithogenity. The gallbladder appeared morphologically normal in 61% of patients with symptomatic gallstones. (5) An increased frequency of gallstones during the last 30 years was only observed in the age group under 1 year.