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G Delling

Publications and source records attributed to G Delling.

At least 37 records · Page 2Linked to original sources
PubMed1990

[A quantitative analysis for determining porosity of pre-compressed and vacuum-mixed bone cement].

The porosity and the mechanical strength of 64 bone cement specimens were investigated. Different types of mixing procedures were tested: 1) hand, 2) compression, 3) vacuum and 4) the combination of vacuum stirring and compression. The differences in porosity and mechanical stability are remarkable. In relation to hand-mixed bone cement all techniques are leading to a reduction in the number of cavities. Specimens made by compression are showing a confluence of several small cavities to a few large. There is only a change in the distribution of the embedded gas volume, but not a reduction. The lowest porosity is seen in vacuum mixed specimens.

Bone Cements↗
PubMed1989

[Recent concepts of the organization and structure of human trabecular bone--results of combined 2- and 3-dimensional analysis].

Every loss of bone mass caused by dysfunction of the endocrine glands and mechanically, respectively, is accompanied by changes of the bone structure. For the pathogenetic mechanisms which in man lead to the abolition of the bone structure in osteoporosis the knowledge of the physiological principles of construction is a basic prerequisite. Hitherto performed studies have shown that with the help of two-dimensional section-cuttings a tridimensional reconstruction is either not possible or can be carried out only by means of serial sections and extensive computer procedures in circumscribed parts. For the analysis of the tridimensional structure of the spongiosa a new method of preparation was developed, which renders possible the simultaneous two-dimensional and tridimensional evaluation of the bone tissue. Seven spinal columns of deceased without disease of the skeleton (donors of organs) between the second and seventh decade of life were evaluated from the dens to the fifth body of the lumbar vertebra. Before the fifth decade of life numerous plate-like structures are existing which in form of intermittent wall carriers lead to a stabilization of the vertebral bodies. With growing age a transformation into rod-shaped trabeculae takes place. This change of structure takes place by large perforations within these plates. Additionally, after the fifth decade of life formations of microcallus occur in a size not known up to now. Apparently an additional process of reparation is existing which shows falsely positive results, when using non-invasive techniques. The results demonstrate the occurrence of perforations with growing age and fundamental changes of the structure of the spongiosa.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Oncogenic hypophosphatemic osteomalacia].

In the courses of six years a severe hypophosphataemic osteomalacia, painful motor impairment and multiple rib fractures developed in a 51-year-old man. The symptoms gradually improved within one year under treatment with 3 micrograms daily of 1,25-dihydroxycholecalciferol, 3 g phosphorus and 3 g calcium, and biochemical parameters and the bone scintigram became normal. Ultimately, computed tomography, scintigraphy and digital subtraction angiography revealed a highly vascularized tumour in the condylar aspect of the right femur, and it was chiselled out. Histologically it was a mesenchymal phosphaturic tumour of haemangiopericytoma type of questionable benignity. After the operation the patient was symptom-free for some weeks without any drug treatment, but the latter was then resumed because of renewed bone pain. By now, two years later, he is essentially without pain and has full mobility. However, repeat scintigraphy and angiography revealed renewed tumour growth in the right femoral condyle.

Calcitriol↗
PubMed1989

Platinum disposition after intraarterial and intravenous infusion of cisplatin for osteosarcoma. Cooperative Osteosarcoma Study Group COSS.

Preoperative chemotherapy according to the COSS 86 protocol, including two courses of cisplatin, was used for high-risk osteosarcoma. Patients were randomised to receive either intraarterial (i.a.) or intravenous (i.v.) cisplatin infusions. As measured by flameless atomic absorption spectroscopy (FAAS), platinum (Pt) levels in serum, ultrafiltrate, and urine did not show a decrease in systemic drug availability with i.a. administration. Tumors were surgically removed 3 weeks after the last cisplatin dose and analysed for Pt content and response to chemotherapy. A correlation could not be demonstrated between Pt levels in tumor tissue samples and the mode of CDDP application or extent of tumor cell destruction.

Bone Neoplasms↗
PubMed1989

[Chronic osteomyelitis and cancer of the fistula].

Malignant change following chronic osteomyelitis with draining sinuses is rare (0.38-2.7%). The time from onset of osteomyelitis until malignant changes differs but needs 30 years in an average. Most patients are men between 50 and 60 years of age. If there is any doubt about malignancy (bleeding, tumor growth) biopsy should be performed and repeated if histological findings give no clear diagnosis. Metastases should be excluded by x-ray of the chest, scintigram and CT of the regional lymphnodes. Correct surgical therapy can only be done by amputation or exarticulation of the extremity. Patients who were operated upon malignant carcinoma of a sinus after osteomyelitis ought to be controlled in a regular follow-up including blood test (tumor marker).

Adult↗
PubMed1989

Increase of vertebral density by combination therapy with pulsatile 1-38hPTH and sequential addition of calcitonin nasal spray in osteoporotic patients.

Combination therapy with the biologically active (1-38) human parathyroid hormone peptide and calcitonin using pulsatile and sequential activation of the skeleton for 14 months in patients with low-turnover osteoporosis resulted in an increase in trabecular bone mass. These favorable responses were observed without any significant changes in cortical (forearm) bone mass content.

Administration, Intranasal↗
PubMed1989

[Initial results of the biocompatibility, cytotoxicity and genotoxicity of Aramid].

Tissue biocompatibility of aramid fibres was tested over up to 16 weeks after subcutaneous (A = nine) and intraarticular (B = twelve animals) implantation in the rabbit. Histologically all specimens showed connective tissue ingrowth with interspersed mesenchymal cells. Foreign body giant cells were numerous and demonstrated intracellular dye or aramid particles. Following implantation into the knee joint the aramid ligament was invaded by longitudinally arranged, stress-oriented collagen fibres as soon as four weeks postoperatively. In spite of reactive new bone formation a functional bony anchorage in the bore holes did not take place during the 16 week period. Additional investigations in bacteria (particularly the Salmonella-microsome Assay according to Ames) and mammalian cell cultures showed no evidence for any cyto- or genotoxic effects of aramid fibres.

Animals↗
PubMed1988

Results of a stimulatory therapy of low bone metabolism in osteoporosis with (1-38)hPTH and diphosphonate EHDP. Protocol of study I, osteoporosis trial Hannover.

In contrast to prevention, the therapy of manifest osteoporosis remains a clinically significant problem. So far all therapeutic attempts have yielded unsatisfying results. For this reason we have tried to achieve a positive bone balance by sequential stimulation and inhibition of the osseous metabolism. The therapy consisted of six 14-day courses with 400 units (1-38)hPTH per day and, in addition, starting with the 2nd week of PTH therapy, EHDP 5 mg per kg body weight per day for a total of 2 weeks. Already the initial therapeutic course resulted in a stimulation of decreased bone metabolism which could be documented by an increase in the calcium-47 accretion rate (six patients). An increase of the alkaline phosphatase could be noted (four patients); this, however, did not correlate with the calcium accretion. A positive calcium balance could, nonetheless, only be attained in four of eight patients within this period, while neither the alkaline phosphatase nor the kinetics would allow a prediction of this effect. Changes of the balance coincided with equal changes in the net calcium absorption. The urinary calcium excretion increased temporarily during the therapeutic phase. We were not able to detect an influence on the vitamin D metabolites. Histomorphometric studies did not demonstrate an increase in bone mass in the iliac creast after six therapeutic courses. Nevertheless, progressive deformations of vertebral bodies did not occur. We conclude that already after 2 weeks this therapeutic concept can lead to a stimulation of bone metabolism.

Adult↗
PubMed1988

Histiocytic differentiation in benign and malignant bone tumors.

In this study fresh frozen tissue samples of benign osseous tumors (five non-osteogenic fibromas, one fibrous dysplasia, one chondromyxoidfibroma), tumors of uncertain biological behaviour (eight cases of histiocytosis X, two giant-cell tumors), and of malignant intraosseous tumors (two malignant fibrous histiocytomas, two malignant histiocytosis, four osteosarcomas, one chondrosarcoma and two Ewing sarcomas) were studied with a panel of monoclonal antibodies reactive with monocyte/macrophages and various types of dendritic cells. In addition, tumors were further defined with a broad spectrum of antibodies against filamentous proteins and lymphocyte differentiation antigens. The specimens were stained with a triple-layer immunoalkaline phosphatase protocol. Tumors stained with these antibodies could be roughly divided into two groups. The first group comprised tumors with one predominant cell population reactive with one particular monoclonal antibody. In this group, cases of histiocytosis X were found to be consistently labelled with CD-1 antibodies. The giant-cell tumors showed a very homogeneous staining with certain monocyte/macrophage antibodies (Ki-M8). Nevertheless, even in these tumors, heterogeneity was demonstrated by the occurrence of cells with monocytic differentiation in histiocytosis X and conversely by the occurrence of cells with differentiation antigens of the dendritic cell system in giant-cell tumors. An exception has to be made for the two cases of malignant histiocytosis examined. These tumors were selectively labelled with antibodies against monocyte/macrophages (Ki-M8, IOM-1). The second group comprised tumors showing a high degree of heterogeneity demonstrated by the varying amounts of tumor cells reacting with the applied markers of the monocyte/macrophage and dendritic cell systems. In most cases it was difficult to ascribe labelled cells to the tumor cell population as opposed to an "innocent bystander" inflammatory cell population. This distinction was especially difficult in malignant fibrous histiocytomas underlining the current concept that these tumors are of primitive mesenchymal rather than true histiocytic origin.

Adolescent↗