Biomedical subjects

A Schultheis

Publications and source records attributed to A Schultheis.

3 recordsLinked to original sources

PubMed2006

Extensive H(+) release by bone substitutes affects biocompatibility in vitro testing.

Bone substitutes are widespread in orthopedic and trauma surgery to restore critical bony defects and/or promote local bone healing. Cell culture systems have been used for many years to screen biomaterials for their toxicity and biocompatibility. This study applies a human bone marrow cell culture system to evaluate the toxic in vitro effects of soluble components of different bone substitutes, which are already in clinical use. Different specimens of tricalcium phosphates (TCP) (Vitoss, Cerasorb), nondecalcified bovine bone (Lubboc), demineralized human bone matrices (DBM) (Grafton Flex/Putty), and collagen I/III matrix (ACI-Maix) were tested in Dulbecco's modified Eagle's medium (DMEM) and MesenCult culture solution and compared with a biomaterial-free cell culture. Biocompatibility parameters were cell viability evaluated by phase-contrast microscopy and laser flow cytometry, morphology, and the local H(+) release by bone substitutes. There were significant differences (p < 0.05) between the tested biomaterials and culture solutions. Collagen I/III, non-demineralized bovine bone, and TCP materials showed advantages for cell survival over other tested biomaterials (average values of vital cells/mL MesenCult/DMEM: Collagen I/III: 1090/1083; Vitoss: 893/483; Cerasorb: 471/523; Lubboc: 815/410; Grafton Putty: 61/44; Grafton Flex: 149/57). Especially the DBM materials lead to a significant decrease of pH, which is considered to be a major factor for cell death. DMEM culture solution supports cell survival for those bone substitutes that induce an alkaline reaction, whereas MesenCult media promotes cell vitality in biomaterials, which leads to an acidification of culture solution.

Animals↗

PubMed1995

[Surgical revision of the pilonidal sinus with single shot antibiosis].

For a therapy of the pilonidal sinus there are different surgical and non-surgical methods to be found in literature. In our surgical wing 140 male patients have been operated on this disease from September 1990 to July 1992. 16 cases out of these 140 were re-operations. Using a special surgical technique we applied the excision with a primary closure under single-shot antibiosis in 139 cases. By modifying this antibiosis prophylaxis we could reach a primary success healing rate of up to 96%. A retrospective study among our patients showed a recurrence rate of 5%.

Abscess↗

PubMedDate not supplied

Osteogenic progenitor cell potency after high-dose chemotherapy (COSS-96).

BACKGROUND: Since the first trial of chemotherapy in patients with osteosarcoma the survival rate has gradually improved. For more than two decades, most osteosarcoma patients from Germany, Austria and Switzerland have been treated according to the protocols of the Cooperative Osteosarcoma Study Group (COSS). The uniform treatment concept of a high-dose polychemotherapy pre- and postoperatively improved the survival rate of these patients significantly. One severe side-effect of COSS chemotherapy is multiple osteonecrosis. PATIENTS AND METHODS: In this study the osteogenic stem cell potency of three different tissue types was elucidated after COSS-96 chemotherapy (high-risk arm). Mononuclear cells were obtained from the periosteum, cartilage and bone marrow of a 17-year-old female with a chondroblastic osteosarcoma. The cells were cultivated for 4 weeks in standard medium and stimulated for osteogenic differentiation after the second passage with dexamethasone, glycerolphosphate and ascorbine acid. Two weeks later, the cell cultures were analysed with respect to cell morphology and immunochemical stainings. RESULTS: All cells cultures showed an osteoblastic regeneration potential measured by osteocalcin (OC), osteopontin (OP) and alkaline phosphatase (ALP) expression. Compared to other donor tissues and localizations, the fibula periosteum showed significantly higher osteoblast rates in vitro, whereas collagen II, CD34 and CD45 were not expressed in any culture. CONCLUSION: The results of this study demonstrate the survival of mesenchymal progenitor cells in bone marrow during COSS-96 polychemotherapy, which allows for an osteogenic regeneration in vitro and potentially in vivo.

Adolescent↗