Development of hepatic tissue engineering Fiegel, Henning Cornelius; Kneser, Ulrich; Kluth, Dietrich ...
Pediatric surgery international,
08/2009, Volume:
25, Issue:
8
Journal Article
Peer reviewed
Liver transplantation is still the only treatment for end-staged liver diseases in children. However, donor organ shortage and immunosuppression are major limitations. Thus, approaches of hepatocyte ...transplantation are under investigation. Using cells might permit mass expansion, cryopreservation, and the ex vivo genetic modification of cells. For the development of cell-transplantation techniques, the use of three-dimensional scaffolds as carrier was shown to be advantageous. Polymeric matrices permit the formation of a
neo
-tissue and stimulation by the modification of the matrix surface. Another important issue is to define the right cell type for transplantation. Adult hepatocytes have a limited growth and differentiation potential. In contrast, fetal liver cells (FLC) possess an enormous growth and a bipotential differentiation potential. Thus, these cells may be very attractive as a cell resource for developing cell-based liver replacement. A third major issue in this approach is the
neo
-vascularization. Therefore, the transplantation in a recently developed model using a microsurgically created arterioveno-venous (AV) loop as a central vessel for the
neo-
tissue was used for transplantation of FLC in a fibrin-matrix. Initial results indicated that the transplantation of FLC using the AV-loop transplantation model may be promising for the development of highly vascularized in vivo tissue-engineered liver support systems.
Embryology of the hindgut Kluth, Dietrich, MD, PhD; Fiegel, Henning C., MD, PhD; Metzger, Roman, MD, PhD
Seminars in pediatric surgery,
08/2011, Volume:
20, Issue:
3
Journal Article
Peer reviewed
Normal and abnormal development of the hindgut is still in debate. Normal development of the hindgut critically depends on the cloacal membrane. In this study, scanning electron microscopy of staged ...rat embryos between the gestational days 10-15 was performed to show the normal development of the hindgut and the abnormal development in Danforth's short tail (SD) mice. Our studies in normal and abnormal development indicate that the embryonic cloaca never passes through a stage that is similar to any form of anorectal malformation in neonates, including the so-called “cloacas” in females. To explain the abnormal development in anorectal malformations, further studies are mandatory.
Nailing of the tibial shaft with 2 Prevot nails is the gold standard for tibial shaft fractures in children. This technical report aims to show a simple way to stabilize pediatric distal tibial ...fractures without changing of the operation method.
A retrospective chart review of all distal tibial fractures treated with the modified elastic stable intramedullary nailing (ESIN) method during a 6-year period was conducted. The modified ESIN technique hardly differs from the classic method, other than the addition of 2 other Prevot nails inserted using the same entry point.
Eight children were treated with the modified ESIN. The mean operation duration was 57 minutes (range, 33 to 88 min). In all cases 2 to 4 mm titanium nails were used. None of our patients required a postoperative cast.Within an average of 14.5 days all of the patients could fully bear their weight (2 to 30 d) and full range of motion was reached.
The modified ESIN technique achieves good results regarding stability and early weight-bearing. Therefore, this technique could be applied in unstable distal tibial fractures. Nevertheless, a prospective and biomechanical study is needed to verify our experience.
Level IV-therapeutic studies.
Appendizitis im Kindesalter Stundner-Ladenhauf, Hannah; Metzger, Roman
Monatsschrift Kinderheilkunde,
2019/6, Volume:
167, Issue:
6
Journal Article
Peer reviewed
Zusammenfassung
Die akute Appendizitis repräsentiert die häufigste Ursache des akuten Abdomens. Ausführliche Anamnese und klinische Untersuchung zählen zu den wichtigsten Standbeinen der Diagnose. ...Unterstützt wird dies durch laborchemische Untersuchungen und die Abdomensonographie. Additive bildgebende Maßnahmen sind selten notwendig. Therapeutisch können die offene und die laparoskopische Appendektomie im Kindesalter sicher und effizient durchgeführt werden. Aufgrund des kosmetischen Ergebnisses, der Beurteilungsmöglichkeit des gesamten Abdomens und geringerer Komplikationsraten ist die Laparoskopie der offenen Technik vorzuziehen. Eine Konversion von laparoskopischer zu offener Appendektomie ist selten nötig. Die konservative Behandlung der akuten Appendizitis mithilfe der Antibiotikatherapie allein wird gegenwärtig intensiv diskutiert und in einigen Zentren praktiziert; die Effektivität bzw. Überlegenheit dieser Methode ist jedoch nicht hinlänglich geklärt und Gegenstand intensiver Forschung.
Purpose
Neuroblastoma is a biological, genetic and morphological heterogeneous tumor with a variable clinical course. NCAM is a cell adhesion molecule belonging to the immunoglobulin superfamily with ...structural similarities to cell adhesion molecule L1. The aim of this study was to determine the expression of NCAM in neuroblastoma and to compare the results to the findings of a previous study which examined L1 expression in the same group of patients.
Materials and methods
NCAM expression was investigated on a tissue array with 66 surgically resected neuroblastoma samples by immunohistochemistry with a monoclonal antibody clone 1B6 and peroxidase method.
Results
Strong expression of NCAM was detected in all of the 66 (100%) neuroblastoma tumors in contrast to L1 which was not expressed in all tumors.
Conclusion
In contrast to L1, which was found to predict favorable outcome, NCAM is universally expressed in neuroblastoma. Therefore NCAM represents a marker for neuroblastomas irrespectively of their stages whereas L1 as an indicator for developing neuronal cells seems to identify more mature stages of this tumor. The high grade of NCAM expression might present a prerequisite for establishment of antibody-based therapies.
The molecular mechanisms underlying the regulation of vas deferens (VD) motility and semen emission are still poorly understood. Interstitial cells of Cajal (ICC), which harbour the c-kit receptor ...(CD117), provide the basis of coordinated gut motility. We investigated whether c-kit receptor-positive cells also exist in the normal human VD. Enzyme and fluorescence immunohistochemical techniques were applied on serial sections of human proximal, middle, and distal VD segments (n=49) employing 13 different monoclonal and polyclonal antibodies recognizing the c-kit receptor. The c-kit receptor was detected in either round- or spindle-shaped cells. On account of their antigenic profile, the round- and oval-shaped c-kit receptor-positive cells were identified as mast cells (MC) occurring in all layers of the VD except the epithelium. In contrast, two distinct populations of exclusively c-kit receptor-positive spindle-shaped cells were found within the lamina propria and, rarely, in the inner and outer smooth muscle layers, as well as within the epithelium. Different shaped c-kit receptor-positive MC and IC were present in all layers of the human VD. Our findings demonstrate the presence of different c-kit receptor-positive cells also in the human VD. Their rather ubiquitous distribution within the lamina propria and muscle layers suggests that IC and MC may modulate the neuromuscular transmission and the propagation of electrical signals in multiple systems involved in the draining of fluids. The importance of the c-kit receptor-positive interepithelial cells remains unclear.
Embryology of the testicular descent Fiegel, Henning C., MD, PhD; Rolle, Udo, MD, PhD; Metzger, Roman, MD, PhD ...
Seminars in pediatric surgery,
08/2011, Volume:
20, Issue:
3
Journal Article
Peer reviewed
Numerous researchers studied the morphology of the testicular descent, including the possible function of the gubernaculum. However, a clear illustration of this process is still missing. The aim of ...this paper was to illustrate the embryology of the testicular descent in the rat by scanning electron microscopy. In a first phase of the intra-abdominal testicular descent, the testis moves actively from the lower pole of the kidney towards the bladder neck. In a second inguinal phase the testis enters groin and moves in the developing processus vaginalis peritonei caused by the disappearance of the bulb of the gubernaculums testis.
The interstitial cells of Cajal (ICC) play an important role in the control of gut motility. The recognition that the ICC cell membrane harbors the c-kit receptor (CD117) sparked rapid advancement in ...ICC research on the gut and certain pathologies using immunochemical and molecular methods. The question arises whether ICC exist in the upper urinary tract (UUT) and trigger motility. The present study analyzed the distribution of the c-kit receptor in the normal human UUT compared with various species. Immunohistochemistry (alkaline-phosphatase-anti-alkaline-phosphatase technique, immunofluorescence) was applied on serial sections using monoclonal and polyclonal antibodies recognizing the c-kit receptor. C-kit staining was compared with standard endothelial, epithelial, neurogenic, histiocytic, mast cell, and smooth muscle markers, as well as a negative control. Normal proximal, middle, and distal ureter segments were analyzed in rodents, carnivores, porcines, cow, and humans. In all species the c-kit receptor was detected in either round or spindle-shaped cells. Because of their antigenic profile, the round cells were identified as mast cells occurring in all layers of the ureteral wall except the urothelium and were more frequent in humans. In contrast, the population of spindle-shaped cells was marked only by anti-c-kit receptor antibodies, thus resembling ICC. These ICC-like cells were found among the inner and outer smooth muscle layers and in the lamina propria of all species. In humans, spindle-shaped cells were also found vertically oriented within the urothelium. Our morphological data present for the first time the distribution of ICC in the UUT of various species. The ubiquitous distribution in the entire pyeloureteral complex provides strong evidence that ICC generate electrical pacemaker activity within the UUT as an intrinsic system. Animal studies may help to understand the physiological importance of these ICC-like cells. The significance of these findings needs to be evaluated by functional studies and investigations of certain congenital pathologies with disturbance of the urinary outflow.
Purpose
Neuroblastoma (NBL) is a tumor from neural crest cells, and is the most frequent solid tumor in children. Midkine (MK) is a pleiotropin analogon, which is frequently expressed in neuronal and ...epithelial tumors and is a marker for a poor clinical outcome. The aims of this study were to assess MK expression in NBL and investigate the correlation with clinical outcome.
Methods
Fifty-six specimens of NBL were stained for MK on a tissue microarray by immunohistochemistry (IHC). Fresh frozen tumor tissues were used for RNA isolation, and RT-PCR analysis for MK-mRNA expression was performed. Survival data, risk factors and disease stages were correlated with MK status assessed by IHC and RT-PCR analysis.
Results
MK-mRNA expression was found in the majority of the tumor tissues (75%), whereas MK protein could be detected only in 46% of the NBL by IHC. No correlation of MK status with survival, risk factors or disease stage was observed.
Conclusion
A majority of NBL express MK-mRNA, whereas not all MK mRNA positive tumors showed also a positive MK IHC staining. The high expression of MK-mRNA expression might present a promising target for new adenovirus-based gene therapeutic approaches for the treatment of NBL.
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