Publications by authors named "Sieverts H"

Neuroblastoma is a common childhood tumor comprising cases with rapid disease progression as well as spontaneous regression. Although numerous prognostic factors have been identified, risk evaluation in individual patients remains difficult. To define a reliable prognostic predictor and gene signatures characteristic of biological subgroups, we performed mRNA expression profiling of 68 neuroblastomas of all stages.

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The Trk family consists of three receptor tyrosine kinases, each of which can be activated by one or more of four neurotrophins-NGF, BDNF, NT3 and NT4. Neurotrophins mediate their multiple effects through a number of distinct intracellular signaling cascades regulating such diverse biological responses as cell survival, proliferation and differentiation in normal and neoplastic neuronal cells. Expression of Trk receptors also plays an important role in the biology and clinical behavior of neuroblastomas.

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Growth plate chondrocytes are the target of the hydroxylated vitamin D metabolites 1alpha,25(OH)2D3 and 24,25(OH)2D3. Because studies on the production of these polar metabolites were inconclusive in various in vitro systems, the expression of a potential paracrine/autocrine vitamin D system was examined in primary cultures of rat growth plate chondrocytes using real-time RT-PCR. Compared to UMR cells and renal homogenates primary cultures of growth plate chondrocytes expressed low levels of 25-hydroxy-1alpha-hydroxylase as well as 25-hydroxy-24-hydroxylase.

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Intraoperative radiotherapy (IORT) permits the application of a single large radiation dose to a malignant mass at the time of surgery sparing adjacent normal tissue from irradiation. Since 1996 we have used IORT to treat 13 children with neuroblastoma, stage 3 - 4. In all cases the tumour was not radically resectable at the first operation.

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Background: Neurotrophins mediate their effects by binding to members of the Trk family of receptor tyrosine kinases and to the low-affinity nerve growth factor receptor p75. Nerve growth factor (NGF) has been demonstrated to support survival and differentiation of neuroblastoma (NB) cells by activation of the TrkA receptor. The p75 receptor belongs to the tumor necrosis factor (TNF) family of death receptors and has been suggested as a receptor that mediates apoptosis in neuronal and NB cells.

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A 11-year-old boy with acquired immunodeficiency syndrome (AaS), Varicella-zoster virus (VZV) infection and long-term antiviral treatment suffered from a disorder of contractility of the left ventricle of the heart. Following severe unmanageable vomiting, the patient died and the postmortem examination showed marked involution of the lymphatic system, multiple foci of fibrosis of both ventricles of the heart, and regressive changes of the thyroid gland. Biochemical values of the thyroid gland function were, however, not altered.

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Cerebral Langerhans cell histiocytosis (LCH) is a rare granulomatous disorder which may be primary or secondary or solitary or multiple. Brain structures outside the hypothalamic-pituitary axis are only scarcely involved, even in multisystem varieties. Since there are neither controlled therapeutic trials nor systematic analyses of hitherto reported cases, optimal treatment strategies are not known.

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Anticancer agents have been shown to trigger apoptosis in chemosensitive tumors such as neuroblastomas. We previously identified activation of the CD95 system as one of the key mechanisms for doxorubicin-induced apoptosis in leukemic T cells. Here, we report that therapeutic concentrations of doxorubicin, cisplatinum, and VP-16 led to induction of CD95 receptor and CD95 ligand (CD95-L) that mediated cell death in chemosensitive neuroblastoma cells.

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Recently the intravenous enzyme replacement therapy with modified beta-glucocerebrosidase has become available for patients with M. Gaucher. We report here the considerable improvement of activity and vigor in a 5 year old girl with type 1 M.

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We report a study of seven children with recurrent stage IV neuroblastoma comparing the uptake pattern of 123I-metaiodobenzylguanidine (mIBG) with 99mTc-labeled monoclonal antibody (MAb) BW 575 by the tumor lesions. Immunofluorescence studies of bone marrow had verified specific binding of the antibody to the tumor cells. The majority of tumor sites was detected both by mIBG and MAb scans.

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The authors present the case history of a child with neuroblastoma and early infiltration of the orbit accompanied by bilateral blindness. The typical clinical signs developed later. The thickening of the periosteum infiltrated by the tumor in the lateral wall of the orbit was demonstrated by computerized tomography.

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We have studied the expression of five surface antigens in eight Burkitt's lymphoma cell lines during different phases of the cell cycle and in different growth phases (logarithmic and stationary). Cells were stained simultaneously for surface antigens (fluorescein coupled antibodies) and DNA content (propidium iodide), and dual parameter measurements were performed with a flow cytometer. Analysis of cells in specific cell cycle phases during log-phase growth revealed a 1.

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Cytogenetic studies were done in two cases of Burkitt's lymphoma in homosexual individuals with possible acquired immune deficiency syndrome (AIDS). The chromosomal abnormalities found are consistent with those previously described in the nonendemic form of Burkitt's lymphoma, with one of the two patients having the variant translocation, t(8;22). The production of the kappa light chain immunoglobulin by the tumor cells from the patient having t(8;22) and the occurrence of the different sites of translocation of the duplication of 1 q in the second patient are unusual findings.

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Three cell lines were derived from a homosexual patient with probable acquired immunodeficiency syndrome and Burkitt's lymphoma. The cell lines produce an unusual strain of Epstein-Barr virus which will both transform cord blood lymphocytes and induce early antigens in Raji cells. Translocations between chromosomes 8 and 22 have occurred in all three lines, but the cells synthesize immunoglobulin M with light chains of the kappa type, in contrast to the usual concordance between a translocation involving chromosome 22 and lambda chain synthesis.

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