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Biomedical subjects

G Delling

Publications and source records attributed to G Delling.

At least 145 records · Page 8Linked to original sources
PubMed1992

[Histologic reactions of the bone-implant zone and cortical bone area after long-term hip replacement].

29 femora with cemented hip endoprostheses and 17 age related controls were analyzed regarding different histological criteria. All specimens were processed to undecalcified ultra thin grindings and in addition a few to surface stained block-grindings. The reactions at the bone implant interface in cases without loosening of the implant are: accumulation of macrophages and multinucleated giant cells, fibrous tissue membranes with a mean thickness of 103 microns and mineralization defects near the cement. The mean rate of direct bone/bone-cement contact is 2.7% of the whole cement surface. The phenomenons at the interface were explained as being the result of micromovement and resulting from wear and tear. The cortical bone demonstrates a remarkable loss of bone (up to 60% after 12 years) following an increase of osteoclastic resorption with no change of osteoblast activity. The localization of the bone loss indicates a relation to the new load situation after implantation.

Aged↗
PubMed1992

[Total hip joint endoprosthesis in osteopetrosis].

Albers-Schönberg disease (osteopetrosis) is a rare condition, and it very seldom occurs that a patient requiring a hip endoprosthesis is also suffering from this disease. The report describes the difficulties which may confront a surgeon unprepared for such a case and the author illustrates the problem taking the case history of a 46-year-old patient with X-rays and histological tests as an example. The reasons for implantation of either a cemented or cementless endoprosthesis are discussed.

Femur Head↗
PubMed1991

Undecalcified preparation of bone tissue: report of technical experience and development of new methods.

For reliable quantitative and qualitative analysis of bone specimens undecalcified preparation is essential. The "conventional" technique for this purpose is embedding in methylmethacrylate. Larger bone specimens, highly sclerotic specimens, cortical bone or bone implants consisting of metals or ceramics require modifications of this technique or completely new methods. We report our experience with the undecalcified preparation of 47,700 bone specimens. New techniques such as the cutting of large area sections up to a size of 5 x 6 cm and grinding procedures for completely artefact-free preparation which are applied in special cases are also described. A new technique of combined two- and three-dimensional analysis of bone specimens is presented. In our experience these methods are fundamental for morphological investigation of bone.

Bone and Bones↗
PubMed1991

Morphological typing of chondrosarcoma: a study of 94 cases.

Ninety-four chondrosarcomas of the Hamburg Bone Tumour Registry were reviewed in a retrospective study. The purpose of this study was to examine the morphological characteristics of different types of chondrosarcomas and to describe distinctive features of location, the age distribution and the male to female ratio. Central chondrosarcomas can be divided into classical chondrosarcomas, dedifferentiated chondrosarcomas, mesenchymal chondrosarcomas and clear-cell chondrosarcomas. Five periosteal chondrosarcomas were represented. Classical chondrosarcomas and clear-cell chondrosarcomas show a significant predominance of males; no sex predilection was seen in dedifferentiated and mesenchymal chondrosarcomas. Nearly 60% of classical and mesenchymal chondrosarcomas occur in the trunk. Eighty-five percent of dedifferentiated chondrosarcomas are located in the long bones of the limbs. Clear-cell chondrosarcomas arise in the proximal part of the femur. There is a marked predilection for mesenchymal chondrosarcomas in the second and third decades of life. The average age of patients with classical chondrosarcomas was 54 years, but clear-cell chondrosarcomas occur 10 years earlier and dedifferentiated chondrosarcomas 10 years later. Characteristically, classical chondrosarcomas produce a pure chondroid matrix with variable differentiation of tumour chondrocytes. The most important histological feature of the defifferentiated chondrosarcoma is the close association of two different cellular components. One of these consists of cartilage, which is generally well differentiated. In most of our cases the second component showed features of osteosarcoma (50%). Mesenchymal chondrosarcoma is characterized by concentric infiltration of cartilage islands by small tumour cells. Clear-cell chondrosarcomas show regions of cartilaginous tumour and areas of closely packed, glycogen-rich, large tumour cells with distinct boundaries. Osteoid formation and multinucleated giant cells are present in clear-cell areas. Knowledge of this group of tumours is indispensable for correct histological diagnosis and typing and is important in the design of surgical therapy and the prediction of biological behaviour.

Adult↗
PubMed1991

Local control and survival from the Cooperative Osteosarcoma Study Group studies of the German Society of Pediatric Oncology and the Vienna Bone Tumor Registry.

The use of aggressive chemotherapy undoubtedly has brought about a dramatic increase in the cure rate of osteosarcoma. The authors' investigations have increased the authors' knowledge of chemotherapy for osteosarcoma, the differential efficacy of currently used agents, and the pronounced schedule dependency and relative route independency of their efficiency. The authors were able to confirm the prognostic significance of tumor response after preoperative chemotherapy. Preoperative chemotherapy in itself has facilitated and promoted limb-salvage surgery. Also, more patients can be cured today by use of aggressive thoracic surgery in case of primary or secondary pulmonary metastases. The authors' efforts to steadily increase metastasis-free survival rates by intensifying chemotherapy in this series of studies, however, have been only moderately successful. Still, chemotherapy-related acute toxicity is considerable and increases with aggressiveness of treatment, and the manifestations of late toxicity may continue to increase with follow-up time. Future trials should be targeted toward exploration of the minimum indispensable amount of toxic treatment yielding comparable or even better results than those currently attainable.

Adolescent↗
PubMed1990

Effect of intraarterial versus intravenous cisplatin in addition to systemic doxorubicin, high-dose methotrexate, and ifosfamide on histologic tumor response in osteosarcoma (study COSS-86).

In osteosarcoma, intraarterial (IA) administration of systemic treatment has been advocated to improve local tumor response preparing for, or even obviating, definitive surgery. Because data from the literature did not unequivocally support the local superiority of IA infusion, a comparative study was started in 1986. Preoperative chemotherapy consisted of 45 mg/m2 of doxorubicin on days 1 and 2; 12 g/m2 of high-dose methotrexate on days 15 and 22; and 3 g/m2 of ifosfamide on days 29, 30, 50, and 51 followed on days 31 and 52 by intravenous (IV) versus IA tourniquet infusion of cisplatin (DDP). A strict randomization of patients was not feasible. A balanced distribution of risk factors was strived for by stratifying and allocating the appropriate patients centrally. The infusion time was prolonged from 1 to 5 hours in the IV group, and the DDP dose was reduced from 150 to 120 mg/m2 in both arms when intolerable ototoxicity became apparent. A multivariate analysis was performed to exclude a bias on the response rates from risk factor distribution and from modifications of DDP infusion time and dosage. The overall fraction of histologic good responders (greater than 90% necrosis) was not found to be different after IA versus IV treatment (34/50 [68%] vs. 41/59 [69%]). Intraarterial instead of IV use of DDP within an aggressive systemic treatment does not seem to improve the local tumor response.

Adolescent↗
PubMed1990

[Morphologic study of iliac crest spongiosa in patients with osteoporosis treated with combination therapy of pulsatile administration of parathyroid hormone (1-38 hPTH) and sequential addition of calcitonin nasal spray].

Seven patients with clinically and histologically proven osteoporosis were treated with intermittent doses of parathyroid hormone fragment (hPTH 1-38) in combination with sequential administration of calcitonin by nasal spray. Iliac crest bone biopsies were taken before and after 14 month of treatment. Under treatment we found a moderate increase in the number of osteoclasts without signs of an increased depth of resorption lacunae.No loss of complete trabeculae due to osteoclastic perforation could be demonstrated. In contrast, we found a drastic increase in the layers of osteoblasts covering osteoid tissue by about 100%. Mineralisation defects or endosteal fibrosis were not present in any case. Mean bone volume (BV/TV) increased under treatment from 12.1% to 16.8% (relative increase of 38%) and was due to a thickening of the individual trabeculae in all seven cases. Considering the small number of patients analysed, the described treatment regimen seems to be efficient on a histological point of view.

Administration, Intranasal↗
PubMed1990

Scintigraphic evaluation of tumor regression during preoperative chemotherapy of osteosarcoma. Correlation of 99mTc-methylene diphosphonate parametric imaging with surgical histopathology.

The effect of preoperative chemotherapy (PCT) on the uptake of 99mTc-labeled diphosphonates into tumor bone was quantitatively assessed from serial scan studies of 30 osteosarcomas and correlated with the histomorphological changes determined from the surgical specimens. The parametric images of the tumor blood pool and labeled methylene diphosphonate (99mTc-MDP) plasma clearance by the tumor bone enabled a sensitive distinction to be made preoperatively between a good (greater than 90% tumor cell destruction) and a poor (less than 90% tumor cell destruction) tumor response. Overall accuracy in presurgical prediction of tumor regression was found to be 88% and 96% for the blood pool and 99mTc-MDP clearance measurements, respectively (P less than or equal to 0.0004). In addition, it proved possible to localize resisting areas of viable tumor up to 1.0 cm in diameter. Even at the half-way stage of PCT, a poor response could be reliably predicted (overall accuracy 91% and 100%, respectively; P less than or equal to 0.011). Therefore, 99mTc-MDP parametric imaging is a highly sensitive and specific modality for an objective and accurate assessment of tumor regression during PCT of osteosarcoma.

Adolescent↗
PubMed1990

Elongation of fetal chick long bone in vitro is formed by a mitogenic activity preparation from porcine bone.

Elongation of fetal chick long bone rudiments is formed by a mitogenic activity from porcine bone in vitro. Fractions of mitogenic activity from a heat- and acid-treated extract and from sequential chromatography on hydroxyapatite and from gel-filtration in 4 M guanidine-HCl increase diaphyseal elongation of metatarsals. The bone elongation-forming activity is associated with the mitogenic activity estimated by the incorporation of [3H]-methyl thymidine into the DNA of cells from embryonic chick periosteum. Histological examination of the mitogen-treated embryonic chick long bone shows that the partially purified fractions with a preferential effect on osteogenic cells increase diaphyseal elongation via cartilage cell proliferation.

Animals↗
PubMed1990

The concept and treatment of osteoporosis.

Osteoporosis is a dynamic process, thought to be caused by an uncoupling between osteoblast and osteoclast activity. Altered pulsatile secretion of growth hormone and parathyroid hormone (PTH) have been proposed as pathogenetic factors for this unbalanced coupling. The anatomical lesions are believed to be reversible until trabecular perforations develop, if fractures already occurred the anatomical defect is permanent. It is helpful to classify osteoporosis in stages of increasing severity depending on bone density and the presence of fractures. Theoretically, if the bone density is above the fracture threshold, then the only therapeutic goal is to maintain the bone mass. If instead the mineral density is below the threshold, an active therapy is needed with drugs that can possibly increase the skeletal mass. Osteoporosis with multiple fractures cannot be reversed. The authors propose a promising pharmacologic treatment for osteoporosis, based on the combination of human PTH-(1-38) and intranasal salmon calcitonin. If started in the early stages of the osteoporotic process, this regimen may restore the initial bone mass. In more advanced stages, only a correction of the metabolic defect is possible, but the irreversible vertebral deformities are not affected. On the basis of the results, cyclic therapy with human PTH-(1-38) and salmon calcitonin represents a good treatment choice for osteoporosis.

Bone Density↗
PubMed1990

Homozygous deletion within the retinoblastoma gene in a native osteosarcoma specimen of a patient cured of a retinoblastoma of both eyes.

In a native osteosarcoma specimen from a patient cured of bilateral retinoblastoma eight years ago, we found a deletion of a 7.5 kb HindIII fragment within the retinoblastoma gene. Our results contribute further evidence that the 7.5 kb fragment harbors a Breakpoint Cluster Region (BCR) in osteosarcoma. In tumor tissue of another osteosarcoma patient the retinoblastoma gene did not reveal any defect on DNA or mRNA level, suggesting different transforming events in this patient.

Adult↗