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Biomedical subjects

G Jundt

Publications and source records attributed to G Jundt.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Bone biopsies of cortical bone segments (technique, evaluation)].

13 drill biopsies were microscopically examined and evaluated in respect of their histologic quality. 8 biopsies were obtained with a diamond hollow cutter, the other 5 specimens were sampled with a modified milling cutter according to Burkhardt. Regarding proper evaluation of bone biopsies e.g. in cases of osteomyelitis, factors as presence of bone marrow cavity or drill powder play an important role. Considering these factors the modified milling cutter according to Burkhardt yields, precise and careful handling provided, better results than the diamond hollow cutter.

Biopsy↗
PubMed1992

[The radiological findings in adamantinoma of the long tubular bones].

The radiological findings of adamantinomas of long bones are described in 22 patients. The diagnosis was confirmed by a team of experts (pathologist, radiologist, orthopaedic surgeon) of the "Bone tumour study group" at the German Cancer Research Center. There were 12 male and 10 female patients aged 5 to 67 years (most commonly in the second and third decade). In 21 patients the tibia was involved and in one patient the fibula. The tumour was nearly always in the diaphysis (20 cases). The most striking radiological feature was a diaphyseal lesion confined to the bone showing multicentric translucencies. The latter showed surrounding or central ring shaped or focal areas of increased density. The lesions tended to be longitudinal, averaging 11 cm (between 3 and 25 cm). All lesions showed a sclerotic margin separating it from normal bone, at least over part of the lesion. Expanding lesions were mostly separated from the soft tissues by a bony rim (18 cases).

Adolescent↗
PubMed1990

Immunoelectron microscopy of osteonectin and type I collagen in osteoblasts and bone matrix.

The pathway of production, secretion, and extracellular deposition of type I collagen and osteonectin was studied by immunoelectron microscopy using respective polyclonal antibodies. Protein A gold and immunogold methods yielded to similar results in human callus tissue used as a model of bone formation. The intracellular distribution of osteonectin in active osteoblasts is found as a faint immunolabeling of vesicular Golgi fields and some lamellae of rough endoplasmic reticulum. A more intensive labeling occurs in opaque cytoplasmic vesicles pointing to the process of secretion as some of the vesicles are connected with the basal cell membrane. Our type I collagen antibody did not label the respective intracellular compartments. Extracellularly, the type I collagen antibody showed a continuous labeling from the immature subcellular osteoid to the mineralized bone. Osteonectin antibodies were bound first to the deeper layer of osteoid maturation with intensity increasing below the mineralization front. Osteonectin is thought to be associated with mineralization of bone matrix.

Antibodies↗
PubMed1989

Immunohistological demonstration of osteonectin in normal bone tissue and in bone tumors.

Osteonectin is a noncollagenous protein of bone which is believed to be bone specific, since its concentration in bone tissue is 500- to 1000-fold higher than in other connective tissues. Immunohistochemistry with polyclonal osteonectin antibodies shows a highly specific marking of actively matrix-producing osteoblasts. Osteonectin is involved in the process of osteoid maturation and mineralization. Immunohistochemistry of osteonectin antibodies proved to be a valuable tool in the diagnosis of bone tumors. Since osteonectin production seems to be an early event in the differentiation of cells of the osteoblastic lineage, immunoreactivity of osteonectin antibodies is observed in types of osteosarcoma lacking osteoid production (anaplastic, fibroblastic) while corresponding types of soft tissue tumors remain unstained.

Bone Neoplasms↗
PubMed1989

Immunocytochemical identification of osteogenic bone tumors by osteonectin antibodies.

18 bone-forming tumours and tumour-like lesions were investigated immunocytochemically for the presence of osteonectin. A group of non-bone-forming skeletal tumours (five cartilage-forming tumours, four Ewing sarcomas and five extraskeletal sarcomas) served as controls. The studies showed that osteonectin antibodies react reliably with benign and malignant bone-forming tumours (two cases of fibrous dysplasia, three osteoid osteomas, 13 osteosarcomas). This finding was supported by protein blot studies. Osteonectin is formed by cells which do not yet possess the morphological phenotype of osteoblasts and may be regarded as a "differentiation marker" of the osteoblastic lineage. Only chondroid bone (tissue in which chondrocytes were surrounded by osteoid matrix containing type I and type II collagen) showed a positive reaction. All other primary skeletal tumours and extraskeletal soft tissue tumours were completely negative.

Antibodies↗
PubMed1988

Immunohistochemical study of osteonectin in various types of osteosarcoma.

Polyclonal antibodies against osteonectin, a 32 kd non-collagenous bone protein, were applied for the histogenetic identification of variously differentiated osteosarcoma tissues. A strong positive reaction was found in matrix-producing osteosarcoma cells of the osteoblastic type, but pleomorphic or fibrosarcomatous osteosarcoma tissues reacted focally positive as well. Because the production of osteonectin depends on the osteoblastlike function of the individual tumor cell, a homogeneous immunocytochemical staining of all tumor cells cannot be expected. Nevertheless, the immunocytochemical demonstration of osteonectin in osteolytic tumors that produce no or scarcely any matrix seems to be a valuable tool for establishment of their osteogenic origin.

Animals↗
PubMed1987

Osteonectin--a differentiation marker of bone cells.

Bone matrix consists of type-I collagen and non-collagenous proteins. The latter represent only 10% of its total protein content. Since type-I collagen is also present in various other connective tissue sites (e.g., skin) it cannot be considered as bone specific. Among the non-collagenous components osteonectin--a 32 kilodalton (KD) glycoprotein linking mineral to collagen fibrils--is thought to be bone specific due to its biochemical properties. In the present study various skeletal and non-skeletal tissues were investigated for the presence of osteonectin by means of immunocytochemical methods. Two polyclonal antibodies against human and bovine osteonectin were applied. Immunocytochemically, osteonectin could be demonstrated in active osteoblasts and osteoprogenitor cells as well as in young osteocytes, while aged, quiescent osteocytes did not contain the protein, suggesting that the protein is a marker of the osteoblastic functional differentiation of bone cells. Osteonectin was absent in all non-skeletal tissues with the exception of chondrocytes in so-called mineralizing chondroid bone.

Antibodies↗
PubMed1986

High dosage desferrioxamine therapy in a female patient with acquired aplastic anaemia and transfusion siderosis.

A 32 year old woman with severe aplastic anaemia required frequent transfusions and consequently developed hyperferrioxaemia (54 microMol/l) and hyperferritinaemia (1,700 ng/ml). For the treatment of transfusion siderosis she was given 18 high dose courses each comprising 35 g of desferrioxamine. Because of pre-existing thrombocytopenia (platelet count 5 X 10(9)/l) the iron chelating agent was given by continuous intravenous infusion over 3 1/2 days. High dose desferrioxamine had to be abandoned because of severe bone pain. The desferrioxamine infusions achieved a negative iron balance, iron loss after each infusion being 100 to 200 mg in the urine and 400 mg in the faeces. Serum iron and ferritin concentrations fell almost to normal. This report shows that faecal iron excretion must be taken into account in assessing the balance of iron input and output during desferrioxamine treatment.

Adult↗
PubMed1986

S-100 protein in amelanotic melanoma. A convenient immunocytochemical approach compared to electron microscopy.

16 amelanotic melanomas were investigated immunocytochemically using two different antibodies against S-100 protein. In six cases electron microscopy was carried out. All 16 tumors showed a positive reaction for both antisera in epithelioid as well as in spindle-shaped tumor cells. Ultrastructurally the six investigated tumors contained stage II to IV melanosomes. Immunocytochemical and electron microscopical results are compared and discussed with regard to their significance in routine surgical pathology.

Adult↗
PubMed1984

Small cell neuroendocrine (oat cell) carcinoma of the male breast. Immunocytochemical and ultrastructural investigations.

A case of small cell neuroendocrine (oat cell) carcinoma of the breast in a 52-year old male is presented. Oat cell carcinomas have been reported in various extrapulmonary sites, but this is the second case of a primary oat cell carcinoma of the breast and the first one to have been documented in a male. The tumor was investigated histologically, immunocytochemically and ultrastructurally. The relationship to so-called "carcinoid" mammary tumors is discussed.

Breast↗
PubMed1984

Sarcoma of the lung in a pacemaker pocket--simple coincidence or oncotaxis?

An 82-year-old man developed a soft-tissue sarcoma in the subpectoral pocket of a titanium-covered pulse generator that had been replaced 8 months previously without evidence of tumor. The tumor represented a metastatic manifestation of a malignant fibrous histiocytoma situated in the contralateral lower pulmonary lobe. The patient died some weeks postoperatively due to cachexia. Autopsy revealed no further metastases. The appearance of cancer in patients with pacemakers is probably coincidental and not related to material or electrochemical stimulation, although the site of the generator pocket might be oncotactic because of the irritation that would trap tumor cells and provide disruption in the intracellular endothelial barrier allowing migration of the tumor cells into tissues. Possible causes and relationships are reviewed.

Aged↗