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Biomedical subjects

H Abts

Publications and source records attributed to H Abts.

11 recordsLinked to original sources

Visualization of brainstem perfusion using a high spatial resolution SPECT system.

The authors explored the high spatial resolution of a three-head rotating SPECT system, equipped with lead super-fine fanbeam collimator. The brainstem was high-lighted in a three-dimensional reconstruction, showing perfusion small structures such as mesencephalon, pons, and medulla oblongata. The visualization of brainstem perfusion sets new landmarks in functional neuroimaging and, moreover, was obtained with a commercially available three-head SPECT system.

Brain Stem

Hodgkin and Reed-Sternberg cells express interleukin 6 and interleukin 6 receptors.

Interleukin 6 (IL-6) is a pleiotropic lymphokine which can stimulate a variety of cells including B and T lymphocytes. It has been suggested that IL-6 plays a crucial role in several diseases such as human plasmacytoma, cardiac myxoma or Castleman's Disease by autocrine or paracrine stimulation. To analyse whether IL-6 is involved in the biology of Hodgkin's Disease (HD), we investigated the expression of IL-6 and IL-6 receptor (IL-6R) in cell lines and primary specimens from patients with HD. IL-6 specific transcripts were detected in three out of six HD derived cell lines by Northern blot analysis and in the culture supernatants of four HD derived cell lines by ELISA. Its biological activity was confirmed by proliferation of an IL-6 dependent cell line. By in-situ hybridization experiments IL-6 specific transcripts were detected in Hodgkin (H) and Reed-Sternberg (RS) cells in primary tissues in two out of three patients. mRNAs specific for the IL-6 receptor were detected in five HD derived cell lines. Staining of HD derived cell lines revealed expression of the receptor molecules in five cell lines; Western blot experiments confirmed the 80kDa receptor protein in the cells. Immunohistology in primary specimens revealed expression of the receptor molecules on H and RS cells in 8 out of 16 cases with HD. Expression was mostly detected in the mixed cellularity subtype of HD. Elevated levels of IL-6 were detected in the sera of more than 50% of patients with HD. Taken together our data suggest that IL-6 might be involved in the biology of HD.

Adolescent

Clinical and pathophysiological aspects of neurological complications in renal failure.

A review of the neurological complications presenting in uremia and an account of their presumed pathophysiology is given. With the introduction of different dialytic procedures during the last twenty years, the incidence and severity of neurological complications have declined. Nevertheless, some disturbances related to the uremic syndrome fail to respond to dialytic therapy and these therapeutic measures may even be responsible for the appearance of some new abnormalities. The clinical manifestations of uremic encephalopathy and polyneuropathy are presented. The review of the presumed pathophysiology of these syndromes illustrates the still existing controversies. Nevertheless, some promising new lines of research are reviewed. In addition, some complications of uremic treatment, including dialysis disequilibrium syndrome and dialysis encephalopathy are presented.

Brain Diseases, Metabolic

Expression of interleukin-6 and interleukin-6 receptor in Hodgkin's disease.

Interleukin-6 (IL-6) is a multipotent lymphokine that can mediate differentiation of B cells into Ig-secreting cells, stimulate the growth of plasmacytomas, hybridomas, and T cells, and induce acute-phase proteins in liver cells. It has been suggested that IL-6 is involved in the pathogenesis of several diseases by autocrine or paracrine pathways. To examine whether IL-6 is possibly involved in the pathophysiology of Hodgkin's disease (HD), we analyzed the expression of IL-6 and IL-6 receptor mRNA and protein in cell lines and primary specimens from patients with HD. IL-6-specific transcripts were detected in three of six HD-derived cell lines by Northern blot analysis. In the culture supernatants of four HD-derived cell lines, IL-6 was detected by radioimmunoassay. Biologic activity of IL-6 was confirmed by proliferation of an IL-6-dependent cell line. In situ hybridization experiments showed IL-6-specific transcripts in Hodgkin (H) and Reed-Sternberg (RS) cells in primary tissues of two patients. In addition, mRNAs specific for the IL-6 receptor were detected in five HD-derived cell lines. Immunostaining experiments showed expression of IL-6 receptor molecules on H and RS cells in 8 of 16 cases with HD. Thus, our data suggest that IL-6 might be involved in the pathophysiology of HD.

Antibodies, Monoclonal

Human chronic lymphocytic leukemia cells regularly express mRNAs of the protooncogenes lck and c-fgr.

Protooncogenes, the cellular homologues of transforming retroviral oncogenes, have been suggested to participate in malignant transformation of various cell types. The role activated protooncogenes might play in chronic lymphocytic leukemia (CLL) is not yet clear. We investigated the expression of the protooncogenes lck and c-fgr encoding two protein tyrosine kinases by Northern-blot analysis in 21 patients with B-CLL and transcripts of both genes were detected in all cases. In contrast to CLL B cells, normal B cells from peripheral blood of a healthy donor separated by magnetic sorting did not express c-fgr and lck. The results suggest a possible role for these two protooncogenes of the src family in the activation and/or transformation of human B lymphocytes.

Adult

High affinity IL-2 receptors on a Hodgkin's derived cell line.

Hodgkin and Sternberg Reed (H and SR) cells, the putative malignant cells of Hodgkin's disease carry regularly T-cell activation antigens, like CD30 and CD25 (low affinity IL-2 receptor). We have investigated the Hodgkin cell line L540, bearing characteristic markers of H and SR cells for its expression of the low affinity IL-2 receptor (IL-2R) and for IL-2. Expression of the low affinity IL-2R was found on mRNA level, by detection of specific 3.5 kb and 1.4 kb mRNA and on the protein level by immunoprecipitation of a 55,000 mol. wt molecule from detergent extracts of surface iodinated cells, however IL-2 specific mRNA was not detected. Scatchard plot analysis revealed the presence of 2 x 10(3) high affinity IL-2Rs. Crosslinking experiments directly demonstrated the high affinity IL-2R to consist of the 55,000 mol.wt light chain (L), and the 70/75,000 (H1/H2) heavy chains. IL-2 was rapidly internalized by these receptors, suggesting that they can be functional. The expression of functional IL-2Rs might be involved in induction or differentiation of Hodgkin's disease.

Fluorescent Antibody Technique

CD20 positive human B lymphocytes separated with the magnetic cell sorter (MACS) can be induced to proliferation and antibody secretion in vitro.

A method is described for the efficient purification of human B lymphocytes from peripheral blood by magnetic separation. Biotinylated, superparamagnetic particles were coupled to target cells by fluorescein isothiocyanate conjugated avidin and biotinylated monoclonal antibodies directed against cell surface antigens. This combination permitted flow cytometric control of the magnetic separation. Ficoll-Paque-separated peripheral blood mononuclear cells were first eliminated from monocytes by leucine-methyl ester treatment. B cells were enriched to 97% after magnetic depletion of CD3-positive T cells and magnetic enrichment of CD20-positive B cells. The separated B cells could be induced to proliferation and antibody production by various in vitro stimuli.

Antibody-Producing Cells

[Vaginal applicator combination for radium therapy of advanced vaginal and cervix carcinomas].

A vaginal applicator combination for intracavitary radium therapy in cancers of the female genitals was developed. By means of several stages which may be combined moreover with tube filters, different combinations and different radium quantities are applicable which can be adjusted to the results of medical examination using symmetric or asymmetric radium sources. The loading of the applicator combination is executed by straight genuine tube filters which were fixed by weld.

Female