Biomedical subjects

B Leidinger

Publications and source records attributed to B Leidinger.

7 recordsLinked to original sources

PubMed2006

Pitfalls in immunohistochemical assessment of EGFR expression in soft tissue sarcomas.

BACKGROUND: New targeted cancer treatments acting against growth factor receptors such as the epidermal growth factor receptor (EGFR) necessitate selecting patients for treatment with these drugs. Besides carcinomas, soft tissue sarcomas (STS) express EGFR and might thereby be a promising target for this new therapeutic strategy. OBJECTIVE: To test and compare different EGFR antibodies to determine the frequency of EGFR expression in STS. METHODS: 302 consecutive specimens of STS were examined using the tissue microarray technique. EGFR expression levels were assessed by immunohistochemistry using five different commercially available antibodies. Gene amplification status was measured by fluorescence in situ hybridisation (FISH). Immunoreactivity and amplification status were correlated with clinicopathological features and follow up data available in 163 cases. RESULTS: EGFR expression frequency ranged between 0.3% and 52.9%, depending on the antibody and scoring method used. In all, 3.5% of the tumours showed egfr gene amplification by FISH, which correlated with EGFR expression for three antibodies. Only one antibody had independent prognostic value in multivariate analysis and correlated with an unfavourable outcome; egfr gene amplification status showed no correlation with clinical features. CONCLUSIONS: Frequency of EGFR immunopositivity in STS strongly depends on the antibody used, and only one of five antibodies tested predicted an unfavourable clinical outcome. This indicates that choice of primary antibody and scoring system have a substantial impact on the determination of EGFR immunoreactivity.

Adolescent↗

PubMed2005

Treatment of primary malignant bone tumours of the distal tibia.

We treated 15 patients with primary malignant bone tumours of the distal tibia of which 14 were treated by limb salvage surgery. Reconstructions were done by allografts with or without microvascular fibula transfer, by bone transport, by fibula transfer alone or by endoprosthetic replacement. The most successful methods were bone transport and endoprosthetic replacement. However, serious complications with deep infections leading to secondary amputation occurred in four patients and in all reconstruction groups. After a mean follow up of 7 years, no local recurrence occurred, and all patients were alive and free of disease. After radical resection, bone transport in defects less than 15 cm is a viable option. In larger defects in children, allograft with vascularised fibula is an acceptable alternative, but amputation still has a role in this group. In adults, endoprosthetic replacement with proper soft tissue coverage is a viable option in cases with large bony defects.

Adolescent↗

PubMed2004

High level of beta-hCG simulating pregnancy in recurrent osteosarcoma: case report and review of literature.

PURPOSE: A high serum level of beta human chorionic gonadotropin (hCG) normally indicates pregnancy in healthy women. We were confused by this finding in one of our patients. This 18-year-old girl presented with amenorrhoea of 1-month duration, a positive pregnancy test and a high beta-hCG serum level although taking contraceptives. Pregnancy was excluded by ultrasound. Three years previously, she had had an osteosarcoma of the humerus. The tumour initially had been wide resected and had shown a good response to neoadjuvant chemotherapy with COSS-96-protocol. METHODS: We reviewed the original histological result and the literature about possible similar findings. We analysed therapeutic options and the value of beta-hCG levels as a therapy monitor. RESULTS: During examination we detected a recurrent osteosarcoma of the left humerus. The local relapse evidently expressed beta-hCG which, retrospectively, could only sparsely be shown in the primary resectate. After intralesional surgery, chemotherapy and radiotherapy levels of beta-hCG normalised. CONCLUSION: Osteosarcoma very rarely is able to produce a paraneoplastic syndrome by high levels of beta-hCG. This may well be of diagnostic value and offer an additional monitoring tool. It can indicate tumour recurrence and dedifferentiation.

Adolescent↗

PubMed2000

[Not Available].

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Disease↗

PubMedDate not supplied

[Ablative and extremity salvage tumor surgery of the lower extremity--a 10 year comparison].

AIM: The treatment of choice for local tumor control was amputation in the 1970's. Nowadays, limb salvage procedures have become the new standard, implicating that limb salvage surgery results in a better quality of life. This study attempts to prove this hypothesis. METHOD: In total, 102 patients who survived longer than ten years after tumor treatment of the lower extremities were investigated, of these, 71 patients underwent ablative procedures compared to 31 patients with limb salvage surgery. Operative revisions, education level, and occupational situation were evaluated in both groups. To analyze the outcome of every patient regarding functional results, quality of life, life contentment, and social parameters, the functional evaluation system of the Muskulo-Skeletal-Tumor Society (MSTS), the Freiburger Life-Contentment-Questionnaire (FLZ) and the Quality of Life Questionnaire (QLQ-C-30) of the European Organization of Research and treatment of Cancer (EORTC) were used. RESULTS: Patients treated with a limb salvage procedure underwent more surgical revisions (p < 0.000). Educational level and occupational situation showed no difference in both groups. Functional results reached similar levels in both groups (74.6% vs. 73.8%). Life contentment and Quality of Life measurements showed good results in both groups. The FLZ-questionnaire showed significantly better results for the ablative group in some items. CONCLUSION: The type of surgical local therapy of lower extremity tumors has no measurable effect on quality of life according to long-term follow-up in lower extremity tumors. In cases with a risk of inadequate margins when performing limb salvage surgery, an ablative procedure should be preferred.

Activities of Daily Living↗

PubMedDate not supplied

[Correction of deformities with conventional and hexapod frames--comparison of methods].

AIM: Distraction osteogenesis for the correction of deformities with an external fixator is well established. The hexapod principle of robotic technique was invented for the Ilisarov apparatus (e. g. Taylor-Spatial-Frame/TSF). Treatment with conventional frames needs a patient-customised frame mounting. This demanding procedure is markedly reduced using this technology. The aim of this study was to analyse the value of the hexapod principle in external fixation. METHOD: The potential of a frame to correct deformities is limited by its work space. The geometry of a conventional frame is different from the geometry of a hexapod frame, which is the reason for their different work spaces. The work space of the hexapod frame is compared to the work space of a conventional frame. Important parameters for this analyses are minimal and maximal frame heights and the potential of correction. RESULTS: The minimal frame height of hexapod fixators is higher compared to conventional Ilisarov fixators. The standard hexapod frame (TSF 155 mm ring diameter) can correct 23 degrees of angulation, 36 mm of shortening, 71 mm of translation and 43 degrees of rotation without changing the telescope rods. The standard conventional frame (160 mm ring diameter) can correct 90 degrees of angulation, 100 mm of shortening, 25 mm of translation and 12.5 degrees of rotation without remounting of the frame. CONCLUSION: The different work spaces of the different frames result in consequences for their clinical application. The hexapod frame has more power to correct translation and rotational deformities than a conventional frame. Correction of extensive angulation and shortening deformities almost always needs an exchange of telescopic rods. Conventional frames are usually able to correct these deformities with the primary mounting. Because of its increased minimal frame height, the indication for hexapod constructs in child orthopaedics can be limited.

Adolescent↗

PubMedDate not supplied

[Limb lengthening with a fully implantable mechanical distraction intramedullary nail].

AIM: The morbidity of fixator-assisted distraction osteogenesis should be reduced by intramedullary lengthening devices. The ISKD (intramedullary skeletal kinetic distractor) is a new, fully implantable mechanical lengthening nail. In a prospective cohort trial the possibilities and limitations of the device used on femur and tibia are examined. METHODS: 22 patients with a mean age of 25 (range: 16-46) years were treated with an ISKD for femoral (n = 16) and tibial (n = 6) lengthening. The average leg length discrepancy was 48 (range: 25-80) mm. The follow-up was 21 (range: 7-37) months. Clinical and radiological results and complications were evaluated. RESULTS: The results of femoral and tibial applications of the ISKD are different. At the tibia, in three patients a pseudarthrosis occurred and slow callus formation was observed twice. An equinus contracture became evident in 2 patients. At the femur, in one case the lengthening was not accomplished with the device. Five patients were manipulated under anaesthesia at least once to achieve the aim of distraction. Three of these patients received retrograde implantation of the ISKD. An infection or interlocking screw failure was not observed either at the femur or the tibia. CONCLUSION: The ISKD reduces fixator-associated problems but incorporates its own difficulties which are mainly based on the guidance of the device. Careful patient advice in monitoring the lengthening process is mandatory. At the femur 8 cm of lengthening can be achieved but the nail tends to "block". Proper reaming and osteotomy techniques are important. A lengthening of more than 1 mm/day is recommended to prevent early consolidation. At the tibia weak callus formation and soft tissue contractures occur, therefore not more than 4 cm lengthening should be planned, the distraction speed has to be reduced noticeable below 1 mm/day and the initial immobilisation should be for more than a week.

Adolescent↗