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Biomedical subjects

Moritz M Ziegler

Publications and source records attributed to Moritz M Ziegler.

8 recordsLinked to original sources

Surgical management of pulmonary and gastrointestinal complications in children with cystic fibrosis.

PURPOSE OF REVIEW: Cystic fibrosis is a common disorder, affecting as many as 1:2500 Caucasian live births. Despite improved medical management, disease-specific complications are common and are responsible for substantial morbidity and ultimately mortality. Both pulmonary and gastrointestinal complications of cystic fibrosis are well known; however, the complications requiring surgical intervention in the pediatric population are infrequent. We provide a detailed review of the cystic fibrosis-associated pulmonary and gastrointestinal complications and potential surgical options for management in children with cystic fibrosis. RECENT FINDINGS: Recent operative approaches are described that include application of minimally invasive surgical techniques primarily for intrathoracic disease. Novel medical therapies are also presented. Finally an attempt is made to put in perspective those surgical care advances that have had a benefit on disease outcomes. SUMMARY: This report will provide the physician caring for the child with cystic fibrosis an understanding of those disease complications that will require surgical consultation and potential operative intervention.

Child↗

Operative strategies for necrotizing enterocolitis: The prevention and treatment of short-bowel syndrome.

Necrotizing enterocolitis (NEC) is the leading cause of short-bowel syndrome (SBS) in infancy. Studies on the acute medical and surgical management of NEC have traditionally focused on short-term morbidity and mortality, with less emphasis on long-term outcomes. Acute surgical management of NEC involves the often competing priorities of controlling sepsis and preserving bowel length. Bowel-preserving strategies for NEC, designed to limit SBS, are based on peritoneal drainage, limited resection, or a combination of both. Drainage-based strategies are generally favored in smaller neonates, while laparotomy-based strategies are favored in larger patients, especially those with a more limited extent of intestinal injury. Comparisons of drainage-based approaches and resection-based approaches are limited by confounding variables, and neither approach is clearly superior with regard to subsequent SBS. These traditional as well as more creative approaches to bowel preservation have application in NEC, yet they depend on a series of patient and treatment characteristics that include the ability of diseased but viable bowel to recover both absorptive and motility function after acute NEC, the ability of the infant to tolerate appropriately drained intraperitoneal contamination, and the ability of the injured intestine to subsequently undergo intestinal adaptive change. In addition, there are a series of operative options that have been designed to mitigate the impact of SBS once it is established. These procedures are not uniquely applied exclusively for NEC-induced SBS. However, strategies that slow intestinal transit, improve peristaltic function, or enhance mucosal absorptive function each have application in the management of SBS.

Digestive System Surgical Procedures↗

Pediatric surgical training: an historic perspective, a formula for change.

BACKGROUND/PURPOSE: American pediatric surgical education has more than a 65-year history of formalizing the organization and the curriculum of the training process. However, never before have so many simultaneous internal and external forces appeared on the horizon that have the collective potential of influencing the quality of future pediatric surgeons. It is the purpose of this study to identify and detail these opportunities, compare them with the historical past, and propose the beginnings of a strategy to control the destiny. The ultimate goal should be to continue to assure that pediatric surgeons are of the highest attainable quality that will optimize the surgical health of America's children. METHODS AND RESULTS: Using a current literature review, 7 specific influencing forces have been identified: a declining applicant pool, the generation-X factor, medical economics, early specialization of training, restricted residency work hours, pediatric surgical manpower, and competency-based surgical education. An effective response to these forces is multifactorial, but a first need might be consideration of a new educational oversight organizational structure for pediatric surgery. Thereafter, specific curricular reform is needed to match the strengths of the candidates as well as the training programs. Finally, as a specialty field we must assert the leadership needed to define optimal educational outcomes. CONCLUSIONS: This report defines the educational history and the contemporary influencing forces, and it proposes a strategy to assure that pediatric surgical education exceeds the needs of America's children into the future.

Adult↗

Fetal tissue engineering from amniotic fluid.

BACKGROUND: We have recently shown, in an animal model, that amniotic fluid can be a source of cells for fetal tissue engineering. This study was aimed at determining whether fetal tissue constructs could also be engineered from cells normally found in human amniotic fluid. STUDY DESIGN: Cells obtained from the amniotic fluid of pregnant women at 15 to 19 weeks of gestation (n=6) were cultured in Dulbecco's Modified Eagle's medium (Sigma Chemical, St Louis, MO) containing 20% fetal bovine serum and 5 ng/mL basic fibroblast growth factor in a 95% humidified, 5% CO(2) chamber at 37 degrees C. A subpopulation of morphologically distinct cells was then mechanically isolated from the rest and selectively expanded. The lineage of this subpopulation of amniocytes was determined by immunofluorescent staining with antibodies against standard intermediate filaments and surface antigens. Cell proliferation rates were determined by oxidation assay. After cell expansion, colonies of amniocytes were statically and dynamically seeded onto both unwoven, 1-mm-thick polyglycolic acid polymer scaffold and acellular human dermis for 72 hours. The resulting constructs were analyzed by scanning electron microscopy. RESULTS: Amniocytes stained positively for smooth muscle actin, vimentin, cytokeratin 18, and fibroblast surface protein, and negatively for desmin, cluster of differentiation 31, and von Willebrand's factor (Dako, Carpenteria, CA). These findings are consistent with a mesenchymal, fibroblast-myofibroblast cell lineage. Mesenchymal amniocytes could be rapidly expanded in culture, based on results of the proliferation assay. Scanning electron microscopy of amniocyte constructs revealed dense, confluent layers of cells surrounding the polymer matrices and firm cell adhesion to both PGA and Alloderm (Lifecell Corp, Branchburg, NJ) scaffolds. No evidence of cell death was observed. CONCLUSIONS: Subpopulations of fetal mesenchymal cells can be consistently isolated from human amniotic fluid and rapidly expanded in vitro. Human mesenchymal amniocytes attach firmly to both polyglycolic acid polymer and acellular human dermis. The amniotic fluid can be a valuable and practical cell source for fetal tissue engineering.

Amniotic Fluid↗

Cardiac relocation and chest wall reconstruction after separation of thoracopagus conjoined twins with a single heart.

Separation of thoracopagus conjoined twins with a single heart and the twin reversed arterial perfusion sequence yielded a single surviving infant with a protuberant heart covered by ribs and soft tissue from the nonsurviving twin. At 13 months of age, the heart was relocated in the chest after caudal mobilization of the diaphragms. The protective tissue cage was removed and a normal chest contour established. This technique also may be useful in the treatment of thoracic ectopia cordis.

Adult↗

The placenta as a cell source in fetal tissue engineering.

PURPOSE: This study was aimed at determining whether fetal tissue constructs can be engineered from cells derived from the placenta. METHODS: A subpopulation of morphologically distinct cells was isolated mechanically from specimens of human placenta (n = 6) and selectively expanded. The lineage of these cells was determined by immunofluorescent staining against multiple intermediate filaments and surface antigens. Cell proliferation rates were determined by oxidation assays and compared with those of immunocytochemically identical cells derived from human amniotic fluid samples (n = 6). Statistical analysis was by analysis of variance (ANOVA). After expansion, the cells were seeded onto a polyglycolic acid polymer/poly-4-hydroxybutyrate scaffold. The resulting construct was analyzed by both optical and scanning electron microscopy. RESULTS: The immunocytochemical profile of expanded placental cells was consistent with a nontrophoblastic, mesenchymal origin. Their proliferation rate in culture was not significantly different when compared with mesenchymal fetal cells isolated from human amniotic fluid; however, it was greater than previously reported rates for similar cells obtained from postnatal or adult tissues. Construct analysis showed dense layers of cells firmly attached to the scaffold without evidence of cell death. CONCLUSIONS: Subpopulations of nontrophoblastic, mesenchymal cells can be isolated consistently from the human placenta. These cells proliferate as rapidly as fetal mesenchymal amniocytes in vitro and attach firmly to polyglycolic acid scaffolds. The placenta can be a valuable and practical source of cells for the engineering of select fetal tissue constructs.

Cells, Cultured↗