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G Delling

Publications and source records attributed to G Delling.

At least 55 records · Page 3Linked to original sources
PubMed2002

Expression of collagen type I, II, X and Ki-67 in osteochondroma compared to human growth plate cartilage.

In order to characterize the consequences for the process of endochondral ossification we performed an immunohistochemical study and compared the expression of collagen type I, II and X as markers of cartilage differentiation and Ki-67 as a marker of cell proliferation in solitary (7-26 years, n=9) and multiple (11-42 years, n=6) osteochondromas with their expression in human fetal and postnatal growth plates. In fetal and young postnatal controls, we found a thin superficial layer of articular cartilage that stained positive for collagen type I while collagen II was expressed in the rest of the cartilage and collagen type X was restricted to the hypertrophic zone. Osteochondromas from children showed lobular collagen type II-positive areas surrounded by collagen type I. In adults, the separation of collagen type I- and type II-positive areas was more blurred, or the cartilaginous cap was missing. Collagen type X was detected in a pericellular distribution pattern within hypertrophic zones but also deeper between bone trabecula. The proliferative activity of osteochondromas from children younger than 14 years of age was comparable to postnatal growth plates, whereas in cartilage from individuals older than 14 years of age, we could not detect significant proliferative activity.

Adolescent↗
PubMed2001

Improved lumbar vertebral interbody fusion using rhOP-1: a comparison of autogenous bone graft, bovine hydroxylapatite (Bio-Oss), and BMP-7 (rhOP-1) in sheep.

STUDY DESIGN: After disc removal and monosegmental instrumentation of the sheep lumbar spine, interbody fusion was compared for 6 months after administration of autogenous bone graft, hydroxylapatite, or rhOP-1. OBJECTIVE: To determine whether the use of rhOP-1 or hydroxylapatite would improve on the intercorporal fusion achieved by autologous bone grafting. SUMMARY OF BACKGROUND DATA: Spinal fusion often fails or shows loss of correction despite large-scale conventional techniques using posterior and anterior access. Also, additional operations to obtain bone grafts are required, which increase morbidity and strain for the patient, but do not always provide bone with sufficient primary stability and high osteogenic potential. METHODS: Vertebral fusion quality was examined by plain radiograph at 4-week intervals, by scintigraphy at 3 and 6 months, and by computed tomography scan, magnetic resonance imaging, biomechanical testing, and histologic evaluation. RESULTS: All examination methods demonstrated superior fusion after administration of rhOP-1, with radiologic fusion apparent at 4 months. Autologous bone grafts eventually produced bony healing in most cases, albeit of a lower quality than with rhOP-1. Hydroxylapatite use led only to the formation of a tight pseudarthrosis. CONCLUSIONS: The results indicate that rhOP-1 use is an appropriate method for improving interbody fusion in the sheep spine. In addition to offering the potential for improved bone healing, rhOP-1 use may permit less invasive surgery such as transpedicular fusion and the use of cages.

Animals↗
PubMed2001

Loss of the ClC-7 chloride channel leads to osteopetrosis in mice and man.

Chloride channels play important roles in the plasma membrane and in intracellular organelles. Mice deficient for the ubiquitously expressed ClC-7 Cl(-) channel show severe osteopetrosis and retinal degeneration. Although osteoclasts are present in normal numbers, they fail to resorb bone because they cannot acidify the extracellular resorption lacuna. ClC-7 resides in late endosomal and lysosomal compartments. In osteoclasts, it is highly expressed in the ruffled membrane, formed by the fusion of H(+)-ATPase-containing vesicles, that secretes protons into the lacuna. We also identified CLCN7 mutations in a patient with human infantile malignant osteopetrosis. We conclude that ClC-7 provides the chloride conductance required for an efficient proton pumping by the H(+)-ATPase of the osteoclast ruffled membrane.

Adenosine Triphosphatases↗
PubMed2001

Structural analysis of high resolution in vitro MR images compared to stained grindings.

The recent advancement of high resolution magnetic resonance imaging has opened up new avenues for the determination of structural characteristics of the trabecular network, which may significantly improve the diagnosis of osteoporosis. An analysis of the calcaneus in healthy women has shown similar age-related changes when comparing structural parameters in high resolution MR images and BMD as measured by DXA [1]. Here we undertook an in vitro study to further compare structural measurements in MR images with those from stained grindings. A 3D gradient echo sequence on a 1.5 T scanner was used to obtain four contiguous sagittal MR images with a slice thickness of 1 mm and an in plane pixel size of 195 microns. Twenty-one stained grindings with a slice thickness of 1 micron each were obtained from a 3 mm thick slab of the same volume investigated by MR. The stack of stained grindings was also used to simulate the influence of variations in slice thickness and in plane resolution. Results for structural parameters derived from the high resolution MR images differed considerably from those derived from the stained grindings because the MR images are heavily influenced by partial volume artifacts. This finding was supported by simulations which also revealed that even at a slice thickness of 500 microns and an in plane pixel size of 13 microns, accurate results could not be obtained when a histomorphometric type analysis was applied. Results also depended strongly on the segmentation method. However, contrary to the stained grindings, images averaged over several slices reveal the three-dimensional network character of the trabecular structure. New efforts should be undertaken to develop analysis strategies that are more adequate for in vivo high resolution images instead of using analysis techniques applied in classical histomorphometry.

Cadaver↗
PubMed2001

A man with hereditary exostoses and high-grade non-Hodgkin's lymphoma of the bone.

Multiple cartilaginous exostoses (MCE) is an autosomal dominant disorder that can lead to malignant transformation from exostoses to a secondary chondrosarcoma. We present a case report of a 52-year-old man with MCE who had a palpable mass at the left shoulder. At the site of the left proximal humerus, a cartilaginous exostosis was localized, suggesting that the tumor developed by a malignant transformation of an exostosis into a secondary chondrosarcoma. Interestingly, a biopsy showed a diffuse large B-cell lymphoma with Burkitt-like features. To our knowledge, the association of high-grade lymphoma and hereditary exostoses has not been described previously. This case demonstrates that a malignant tumor at the location of a cartilaginous exostosis is not necessarily a chondrosarcoma and that a biopsy is an essential part of the diagnostic work-up.

Bone Neoplasms↗
PubMed2001

[Histological characteristics and prevalence of secondary osteoporosis in systemic mastocytosis. A retrospective analysis of 158 cases].

Mastocytosis is characterized by abnormal proliferation of mast cells especially within the skin and bone marrow and is often associated with osteoporosis. Mast cells can synthesize a variety of cytokines that are known to affect the skeletal system, but the cellular and pathophysiological mechanisms leading to osteoporosis in systemic mastocytosis remain poorly understood. To further characterize mastocytosis-associated osteoporosis we compared bone histomorphometric findings in iliac crest biopsy specimens from 158 untreated patients with mastocytosis. The overall prevalence of mastocytosis in the specimens diagnosed with osteoporosis was 1.25%, but that in patients younger than 45 years was 2.25%. The male-to-female ratio was 1:1, in contrast to 1:2 in osteoporosis. Osteopenia was present in 64% of the patients with mastocytosis, while osteosclerosis was rare (3%). Histological criteria are the concentric increase in mast cells in the perivascular tissue and the increase in elongated mast cells within the marrow space. Histomorphometry showed mastocytosis to be associated with moderate hyperosteoidosis and increased perforating bone resorption, indicated by a significant decrease in bone volume, trabecular thickness, and trabecular number as compared to controls. Osteoclast number was not altered, pointing to a functional effect of mast cells and/or its product on osteoclasts, rather than an effect on osteoclast differentiation. We conclude that although the prevalence of mastocytosis seems to be low, its correct and early diagnosis is crucial for at least 2.25% of younger patients with osteoporosis.

Adult↗
PubMed2001

Gsalpha gene mutations in monostotic fibrous dysplasia of bone and fibrous dysplasia-like low-grade central osteosarcoma.

A series of nine cases with monostotic fibrous dysplasia (FD) and five cases of fibrous dysplasia-like low-grade central osteosarcoma (fd-like lgcOSA) were applied in a mutational analysis. Restriction digestion analysis, single-stranded conformational polymorphism (SSCP) analysis, and repeated sequencing demonstrated a R201H mutation in six cases and a R201C mutation in three cases of patients with monostotic FD. These results demonstrate that the presence of Gsalpha gene mutations is a constant finding in monostotic FD. To our knowledge, this is the first report in the literature investigating Gsalpha gene mutations in lgcOSA, which is one of the most important differential diagnoses of FD because of its low-grade malignant behavior. In four of five cases of fd-like lgcOSA, no mutation has been detected. In one case of this tumor, a R201C mutation could be demonstrated. Because our results demonstrate a low prevalence of Gsalpha gene mutations in this tumor in contrast to monostotic FD, mutational analysis may be an additional helpful parameter in individual cases for the differential diagnosis of FD and fd-like lgcOSA.

Adolescent↗
PubMed2001

The nature of giant cell tumor of bone.

Giant cell tumor of bone (GCT) is a locally osteolytic tumor with variable aggressiveness. In rare cases, pulmonary metastasis can be observed. The lesion most frequently occurs in the epiphysis of long tubular bones of the knee region, predominantly affecting young adults after closure of the growth plate. The characteristic histological appearance of GCT displays a high number of osteoclast-like multinucleated giant cells, which resulted in the classification "osteoclastoma" or "giant cell tumor". Apart from the multinucleated giant cells, there are two mononuclear cell types in GCT. The first one has a round morphology and resembles monocytes. The second cell type is the spindle-shaped, fibroblast-like stromal cell. Cell culture experiments with GCT cells revealed the stromal cell to be the proliferating component of the GCT. The other two cell types, the monocyte and the multinucleated giant cell, were lost after a few cell culture passages. Furthermore, latest results from GCT reveal that the stromal cells secrete a variety of cytokines and differentiation factors, including MCP1, ODF, and M-CSF. These molecules are monocyte chemoattractants and are essential for osteoclast differentiation, suggesting that the stromal cell stimulates blood monocyte immigration into tumor tissue and enhances their fusion into osteoclast-like, multinucleated giant cells. The multinucleated giant cell itself resembles a normal osteoclast that is able to resorb bone leading to extended osteolysis. This new model of GCT genesis supports the hypothesis that the stromal cell is the neoplastic component whilst the monocytes and the multinucleated giant cells are just reactive components of this tumor. Taking this into consideration, the nomenclature of the "giant cell tumor" needs to be reconsidered.

Bone Neoplasms↗
PubMed2001

Corroded nitinol wires in explanted aortic endografts: an important mechanism of failure?

PURPOSE: To analyze surface alterations and fractures observed in the nitinol stent wires of explanted endovascular grafts used for treatment of abdominal aortic aneurysm. METHODS: Twenty-one explanted Stentor devices and 1 Cragg stent were received from investigators in Germany and France. After macroscopy and photography, the explants were cleaned and the polyester coating removed. The frame was examined completely by stereomicroscopy, and irregularities were assayed by scanning electron microscopy and energy dispersive x-ray analysis (EDAX). The observed alterations were classified according to stereomicroscopic and electron microscopic morphology. RESULTS: The mean implantation interval for the endografts was 29.1 +/- 13.2 months (range 5-46). All examined explants, even those retrieved after only a few months in situ, showed pitlike surface damage 10-25 microm in diameter. Larger, irregularly shaped surface alterations were observed in approximately 70% of the explants. Older explants (age >32 months) presented vast regions of decay, with bending of the wire and stress cracks in some areas. EDAX examination revealed decreased nickel concentration in the corroded regions. CONCLUSIONS: Corrosion of the nitinol wire in endovascular grafts is confirmed. Presumably, the observed pitting and irregularly shaped corrosion defects are the precursors of material failure. They weaken the thin wire, which leads to stress cracks and eventually fracture of the stent wire under circulatory pulsation. Cell-induced electrochemical corrosion and active cellular destruction of surfaces are well-known mechanisms that must be investigated for their possible roles in the corrosion of stent metals.

Alloys↗
PubMed2001

Fluoroscopy-guided transpedicular trocar biopsy of the spine--results, review, and technical notes.

The purpose of this study was to evaluate the technique and value of fluoroscopy-guided percutaneous transpedicular trocar biopsy in obtaining diagnostic tissue from vertebral body lesions and to review the current literature. The bone cores from 32 patients who underwent 34 transpedicular Jamshidi trocar biopsies for lesions in the thoracic, lumbar and sacral spine were examined. All samples were examined macroscopically for length and breakage and microscopically for trabeculae, marrow, and artifacts. Each sample was graded for its value for histologic examination. The diagnostic accuracy was assessed by the patient's clinical course and follow-up examinations. In 30 (93.8%) of the 32 patients a confirmed diagnosis or exclusion of pathology could be made. In 31 (91.2%) of 34 biopsies the quality of the specimen was assessed as "excellent". Two (5.9%) specimens were "good" and one (2.9%) was "poor". There were two minor complications (5.9%). Transpedicular biopsy of the spine using a Jamshidi trocar with an internal diameter of 3.1 mm under fluoroscopic guidance can be performed safely and efficiently and provides suitable bone cores for histologic examination. A combined clinical, radiological and pathological approach to the lesions leads to an excellent diagnostic yield.

Adolescent↗
PubMed2000

The effect of extracorporeal shock waves on joint cartilage--an in vivo study in rabbits.

The application of extracorporeal shock waves has become a new mode of treatment for affections of the locomotor apparatus such as calcifying tendinitis, epicondylitis humeri radialis, calcaneodynia and pseudarthrosis. The treatment often takes place in the vicinity of joints. Up to now no systematic data have been published about possible side-effects on joint cartilage. In an in vivo study the effect of extracorporeal shock waves on joint cartilage was evaluated in 24 immature New Zealand White rabbits. The left lateral femoral condyle of each animal was treated with 2000 shock waves of 1.2 mJ/mm2; the right condyle served as control. Macroscopical, radiological and histological analysis at 0, 3, 12 and 24 weeks after treatment showed no pathological changes in the joint cartilage. We conclude that extracorporeal shock wave treatment does not cause damage to the joint cartilage of growing rabbits.

Animals↗
PubMed2000

[Chondroblastoma of the patella with pathological fracture].

Chondroblastoma is a rare benign bone tumor of cartilaginous origin. The typical localization of a chondroblastoma is the epiphysis of long tubular bones--the patella is a very unusual site with an estimated occurrence of 2%. We report a case of a 16-year-old patient with a chondroblastoma of the patella associated with a pathologic fracture. Partial resection of the patella was performed. This is the sixth case in the literature that associates patellar chondroblastoma with fracture.

Adolescent↗
PubMed2000

[Clear-cell chondrosarcoma].

Clear-cell chondrosarcoma is a rare, low-malignant bone tumor. The lesion most commonly occurs in adults, generally in the 3rd or 4th decade. Clear-cell chondrosarcoma has a predilection for the epiphyses of long tubular bones, particularly the femoral head. Radiologically, it is a sharply defined radiolucent lesion. Histologically, it is characterized by large tumor cells with distinct boundaries and a clear cytoplasm. In addition to areas of conventional chondrosarcoma, there are partially mineralized trabecular osteoid formations. On the basis of 16 cases of clear-cell chondrosarcoma, we present the observations of the Hamburg Bone Tumor Register. The cases were examined according to age distribution, location, and radiological and pathomorphological criteria. The proximal femur was the most frequent location; rare manifestations in the rib, os ilium, and distal phalanx of the hand were also present. In 50% of the cases high-malignant osteosarcoma or conventional chondrosarcoma was considered. In addition to the epiphysis of the proximal femur, clear-cell chondrosarcoma can also involve other, rather unusual sites in the skeleton. Knowledge of the histomorphology of this tumor is therefore of crucial importance for the diagnosis.

Adult↗
PubMed2000

Ionogran in revision arthroplasty.

Glass ionomer cement (Ionocem) was developed for use in bone surgery and is reported to be notably biocompatible. Between 1991 and 1994 we performed revision operations for aseptic loosening of arthroplasties of the hip on 45 patients using this material in its granulate form (Ionogran) mixed with homologous bone as a bone substitute. Of these 45 patients, 42 were followed up for a mean of 42 months. Early reloosening of the acetabular component has occurred in ten after a mean of 30 months. Histological examination showed large deposits of aluminium in the adjacent connective tissue and bone. Osteoblastic function and bone mineralisation were clearly inhibited. The serum levels of aluminium were also increased. The toxic damage at the bone interface caused by high local levels of aluminium must be seen as an important factor in the high rate of early reloosening. Our findings cast doubt on the biocompatibility of this material and we do not recommend continuation of its further use in orthopaedic surgery.

Adult↗
PubMed1999

[Computed assisted voice recognition. A dream or reality in the pathologist's routine work?].

During the last 30 years the analysis of human speech with powerful computers has taken great strides; therefore, cost-effective, comfortable solutions are now available for use in professional routine work. The advantages of using voice recognition are the creation of new documentation or archives, reduced personnel costs and, last but not least, independence in cases of unforeseen notification of illness or owing to annual leave. For voice recognition systems to be used easily, a considerable amount of time must be invested for the first 3 months. Younger colleagues in particular will be more motivated to dictate more precisely and more detailed because of the introduction of voice recognition. The effects on other sectors of medical training, quality control, histology report preparation, and transmission can only be speculated.

Artificial Intelligence↗
PubMed1999

[Gorham-Stout idiopathic osteolysis--a local osteoclastic hyperactivity?].

One rare case of so-called massive idiopathic osteolysis Gorham-Stout is presented. In a 77-year-old female patient the whole right femoral head and neck of femur was resorbed within 2.5 month following trauma. As a histologic cause for the osteolysis, a marked stimulation of osteoclasts on the spongiosa, especially intracortically, was observed. The course and the clinical findings are described, and the pathogenesis and treatment are discussed in comparison with the present literature. The results suggest that an early antiresorptive therapy (calcitonin, bisphosphonates) could stop the progressive osteolytic changes.

Aged↗
PubMed1999

[Chondromyxoid fibroma. Morphological variations, site, incidence, radiologic criteria and differential diagnosis].

Chondromyxoid fibroma is a rare benign bone tumor, accounting for less than 1% of all bone tumors. The peak age incidence is the second and third decade of life. Chondromyxoid fibrom occurs in the metaphyseal parts of the major tubular bones, predominantly of the lower extremity. Roentgenograms show, in most cases, a well-demarcated radiolucent lesion. The classic histological feature of a chondromyxoid fibroma is stellate or spindle-shaped cells arranged in lobules in a myxoid or chondroid background. Analysis of 40 chondromyxoid fibromas demonstrates the morphological variation of this tumor. Cases were examined for age distribution, localization, and radiological and histological features. In 85% we found the typical histomorphological pattern. Recurrence rate was 12.5%. In four cases the appearance was uncharacteristic and differentiation from other tumors such as chondroblastoma or chondrosarcoma was quite difficult. By adhering to strict histomorphological criteria, definite diagnosis of chondromyxoid fibroma can be made in most cases.

Adolescent↗