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Biomedical subjects

I Baumann

Publications and source records attributed to I Baumann.

16 recordsLinked to original sources
PubMed1992

Three-dimensional image processing for morphometric analysis of epithelium sections.

The reproducible classification of poorly differentiated abnormal epithelium specimens is still a diagnostic problem. The computer-aided method described here improves the differentiation between benign and malignant epithelium specimens. Hematoxylin and eosin-stained sections of normal squamous epithelium, dysplasia, carcinoma in situ, and carcinoma were scanned in a TV microscope system and analyzed by means of image processing methods on a DEC 5000/200 workstation. From the 15-20 microns thick histological sections, 3-5 focus positions in steps of 1-4 microns were scanned. The segmentation of the cell nuclei was performed automatically by color analysis and geometric operations. For each nucleus the best focus level was selected and at this level the center of the cell was calculated. Graph theoretical methods were applied to analyze the morphometry of the epithelium specimens. The minimal spanning tree was computed in the three-dimensional (3D) space of the sections with the selected centers of the nuclei as vertices. The best feature found for discrimination of the specimens is the average length of all edges in a tree. In the two-dimensional (2D) analysis we had to accept an error probability of about 20% in differentiation of dysplasia and carcinoma. In contrast to this we differentiated normal squamous epithelium, dysplasia, and carcinoma with a correct classification rate of 100% in the 3D analysis.

Carcinoma↗
PubMed1990

Expression of Tac antigen component of bovine interleukin-2 receptor in different leukocyte populations infected with Theileria parva or Theileria annulata.

The Tac antigen component of the bovine interleukin-2 receptor was expressed as a Cro-beta-galactosidase fusion protein in Escherichia coli and used to raise antibodies in rabbits. These antibodies were used for flow cytofluorimetric analysis to investigate the expression of Tac antigen in a variety of Theileria parva-infected cell lines and also in three Theileria annulata-infected cell lines. Cells expressing Tac antigen on their surface were found in all T. parva-infected cell lines tested whether these were of T- or B-cell origin. T cells expressing Tac antigen could be CD4- CD8-, CD4+ CD8-, CD4- CD8+, or CD4+ CD8+. Tac antigen expression was observed both in cultures which had been maintained in the laboratory for several years and in transformed cell lines which had recently been established by infection of lymphocytes in vitro with T. parva. Northern (RNA) blot analysis demonstrated Tac antigen transcripts in RNA isolated from all T. parva-infected cell lines. Three T. annulata-infected cell lines which were not of T-cell origin were also tested. Two of them expressed Tac antigen on their surface. Abundant Tac antigen mRNA was detected in these T. annulata-infected cell lines, but only trace amounts were demonstrated in the third cell line, which contained very few Tac antigen-expressing cells. In all cell lines tested, whether cloned or uncloned, a proportion of the cells did not express detectable levels of Tac antigen on their surface. This was also the case for a number of other leukocyte surface markers. In addition, we showed that the interleukin-2 receptors were biologically functional, because addition of recombinant interleukin-2 to cultures stimulated cell proliferation. Recombinant interleukin-2 treatment also resulted in increased amounts of steady-state Tac antigen mRNA. The relevance of interleukin-2 receptor expression on Theileria-infected cells is discussed.

Animals↗
PubMed1990

[Pattern analytic investigations of blast cells in myelodysplastic syndrome and secondary acute myeloid leukemia].

Blast-cells in Romanowsky-Giemsa stained bone marrow smears from 14 cases of primary myelodysplastic syndrome which consequently developed an acute myeloid leukemia and 28 cases of primary acute myeloid leukemia were analysed by a computer aided high resolution pattern recognition system. As control we used blast-cells from reactive affected bone marrow. Whereas blast-cell types in MDS and secondary AML showed overlapping features and a heterogenous distribution we could distinguish blasts in primary AML compared to "reactive" blasts. Opposite to this blasts in secondary AML showed no different pattern compared to "reactive" blast.

Acute Disease↗
PubMed1990

[Function and pathology of bone marrow stromal cells].

For their lineage commitment and differentiation haematopoietic tem cells need a specific microenvironment. This milieu is formed by bone marrow stroma, which includes lymphocytes, macrophages, fibroblasts, reticular cells, adipocytes, osteogenic and endothelial cells. These cells play different regulatory roles in supporting haemopoiesis. The stroma-stem cell interaction take place by immediate cellular contact. Growth factors and extracellular matrix molecules produced by stromal cells influence the regulation of haemopoiesis as well. This cellular context could be established in different animal models. Impairment of stromal cell function with increased fibroblast proliferation and increased collagen synthesis is an impressive morphological feature of myelofibrosis.

Animals↗
PubMed1990

[Experiences in the diagnosis and treatment of polyneuropathies in patients with malignant monoclonal gammopathy].

4 patients are reported having monoclonal gammopathies, who clinically exhibited a sensomotoric polyneuropathy being progressive during some years. The EMG showed axional failure and secondary demyelisation. In two of the patients an IgG-type multiple myeloma has been revealed, while in the other two ohnes an increase of abnormal IgM-mIg could be demonstrated. In all patients the liquor protein was found increased and the appropriate mIg has been found in the liquor. Immunohistochemically the appropriate immunoglobulins could be demonstrated on the peripheral nerve by means of immunofluorescence method. Electron microscopical studies of nerval biopsies supported the diagnosis of mIg-associated polyneuropathy. References to diagnostics and treatment of mIg-associated polyneuropathy are done.

Aged↗
PubMed1989

A promising genomic transfectant into Xeroderma pigmentosum group A with highly amplified mouse DNA and intermediate UV resistance turns revertant.

Following transfection of genomic mouse DNA into an SV40 transformed fibroblast cell line from a patient with Xeroderma pigmentosum (complementation group A, XPA), a single UV resistant cell clone was isolated out of a total of 10(4) independent transfectants. The recipient XPA cell line has as yet not produced spontaneous revertants among 2.2 x 10(8) cells. The isolated cell clone contains 50-70 kb of mouse sequences which are heavily amplified (500-fold), and has acquired both intermediate resistance to UV killing and intermediate unscheduled DNA synthesis (UDS) capacity. By continued passage without selective pressure, cells were generated, which had lost both the dominant marker gene and repetitive mouse sequences. Single colonies of these cells were still intermediately resistant to UV suggesting that either undetected unique mouse DNA had segregated from the bulk of repetitive DNA, or, more likely, that the initially isolated transfectant was a spontaneous revertant. This documents that a persuasive clone isolated can still be a false positive (spontaneous revertant) and that an extremely laborious approach may lead into a dead end.

Animals↗
PubMed1989

Infection with the intracellular protozoan parasite Theileria parva induces constitutively high levels of NF-kappa B in bovine T lymphocytes.

The intracellular protozoan parasite Theileria parva causes a lymphoproliferative disease of T cells in cattle and uncontrolled lymphocyte proliferation in culture. We have identified and characterized in infected cells the transcriptional activator, NF-kappa B, whose recognition motifs have been identified in several gene enhancers important for lymphocyte-specific gene expression. NF-kappa B is normally constitutively activated in nuclear extracts derived from B cells and can be induced in T cells and nonlymphoid cells by phorbol esters. Theileria-infected lymphocytes contained constitutively high levels of activated NF-kappa B in nuclear fractions and inactive NF-kappa B in cytoplasmic fractions. The inactive cytoplasmic precursor could be activated by treatment of extracts with deoxycholate, which was shown previously to dissociate NF-kappa B from an inhibitor, I kappa B. Treatment of lymphocyte extracts with 3 mM GTP stimulated NF-kappa B binding to its recognition motif in vitro, thereby distinguishing it from a related nuclear factor, H2-TF1. Selective killing of the parasite, which left the host cells intact, resulted in a rapid loss of NF-kappa B from the nuclear fractions and a slower loss from the cytoplasmic fractions. In parasitized cells, NF-kappa B could not be further stimulated by treatment with 12-O-tetradecanoylphorbol-13-acetate whereas in cells treated to remove the parasite, this compound stimulated elevated levels of NF-kappa B. We propose that high levels of activated NF-kappa B are maintained by the presence of the parasite in infected T cells. Similarly, we propose that the high levels of inactive cytoplasmic precursor are a result of increased synthesis due to the presence of the parasite.

Animals↗
PubMed1989

[Low dosage retinol and L-cystine combination improve alopecia of the diffuse type following long-term oral administration].

In a pilot study (I) the efficacy of a new combination therapy for hair loss of the diffuse type was tested in 36 patients, followed by a double blind study with 47 patients. The daily dosage was 18,000 IE retinol, 70 mg L-cystine and 7000 mg gelatin. The clinical efficacy was evaluated by standard methods, such as the preparation of trichograms and measurement of the hair density before and after treatment. The pilot study demonstrated a significant improvement, with reduction of the telogen rate by 8.3%, an increase of the anagen rate by 11%, and an increase of the hair density by 6.9%. In the double blind study (II) the trichogram showed a significant decrease of the telogen rate by 13.5% compared with pathological baseline values. There was no change in the placebo group. The lowered anagen rate of 47.2% was improved by 8%, whereas the mean value in the placebo group decreased from 47.7% to 39.9%. In addition, the percentage of dysplastic anagen hairs improved by 7.4%, as against further impairment with an increase of 26% in the placebo group. During oral therapy no systemic side-effects were detected. We conclude that long-term oral therapy with high doses of L-cystine and gelatin in combination with vitamin A may have beneficial effects on diffuse hair loss.

Administration, Oral↗
PubMed1989

[Testis endothesis surgery. Results of an ambulatory clinical evaluation study].

Under out-patient conditions 13 testicular endotheses of silicone rubber were implanted in local anaesthesia. The mean age of the 11 patients was 44.6 years and minimum follow-up was one year. In all but one case the clinical course was uneventful, in this patient the prosthesis was rejected after a secondary intervention. The follow-up examination did show in all cases clinical, ultrasonographical and cosmetical good results with the 14 g variant for the adult patient. This prosthesis is recommended the further use because of low operative risk, uneventful follow-up and improved body image.

Adolescent↗
PubMed1987

12-O-tetradecanoyl-phorbol-13-acetate induction of the human collagenase gene is mediated by an inducible enhancer element located in the 5'-flanking region.

Genomic clones coding for human fibroblast collagenase were isolated. By constructing and transfecting mutants with 5' and 3' deletion mutations of the 5' control region of the gene into human or murine cells, we delimited a 32-base-pair sequence at positions -73 to -42 which is required for the induction of transcription by the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate. The DNA element behaves as a 12-O-tetradecanoyl-phorbol-13-acetate-inducible enhancer: it mediates the stimulation of transcription to the heterologous herpes simplex virus thymidine kinase promoter and acts in a position- and orientation-independent manner. Differences in enhancer efficiency in different cell lines are interpreted to indicate differences in the activity of a trans-acting factor.

Adult↗
PubMed1987

[Behçet disease and exogenous interferon. A successful treatment study using recombinant alpha-A-IFN].

Up till now no standard therapy for Behçet syndrome has existed. Long-term corticoid therapy is often necessary, although side-effects cannot be avoided. Recent investigations have shown a correlation between high endogenous gamma-interferon serum levels and low activity of the syndrome. A 20-year-old male with severe Behçet's syndrome was therefore treated with recombinant alpha-A-interferon (IFN). The general condition of the patient improved rapidly, together with rapid clearing of the skin lesions. Over a 10.5 week-period the patient received a total dose of 792 million IU recombinant alpha-A-interferon.

Behcet Syndrome↗
PubMed1986

Leukemia-related morphological features in blast cells.

This paper investigates the use of image-processing methods to detect leukemia-related morphological differences in mononuclear blast cells. Routinely prepared Pappenheim-stained blood smears were scanned in a high-resolution color TV-microscope system. Eleven blast-cell classes (OMSBC, T-ALL, OMS, ALL, LBL, IBL, AUL, AML, AMOL, AMMOL, and CML) were analyzed with the nonparametric statistical software program "Classification and Regression Trees" (CART). This paper documents the initial statistical evaluation of 62 leukemia-related morphological features that directly measure and analyze the cell-related quantifiable differences occurring in the various blast cells. The 62 cell image features include both common cytophotometric features, and new texture and color features developed for this project. This study found that each leukemia specimen contains a dominant class of blasts that correlates with the specific leukemia, plus a distribution of blasts from related diseases. The present data suggest the existence of a distribution fingerprint pattern for each leukemia.

Cell Nucleus↗
PubMed1976

[Value and worthlessness of clinical studies in the diagnosis of brain death].

Death was ever determined on the basis of extinguished partial functions of the entire organism (partial death). In intensive medicine with its possibilities of reanimation, with its possibilities of artificial maintenance of breathing and circulation the individual death of man is equated with his cerebral death. It comes only under conditions of reanimation and nearly always shows a clinically recognizable development. Practically above all "the syndromes in the forefield of cerebral death" are of interest as well as its obligatory and optional symptoms, the valency of which was critically tested. A 5-year-analysis (1969 to 1973) of 487 deaths in an internal intensive therapy unit (18% of mortality) was shown that causes, frequency and age distribution of the mortal conditions of disease as well as the average survival time of 4.5 days, in which cases, however, 43% of all deaths occurred within the first 24 hours, very rarely caused us to establish the irreversibility of the loss of the cerebral function on account of an organic dysfunction, but rather resulting from the question of the interruption of an absurd reanimation.

Brain Death↗
PubMed1975

[Myasthenia gravis: surgical treatment with thymectomy (author's transl)].

Thymectomy may be an effective treatment of Myasthenia gravis. 25% of the 16 patients had a complete remission of the disease, 70% remarcable improvement. Half of the patients were able to resume working. Diagnostic methods, surgical and postoperative problems are discussed. Lateral left thoracotomy is recommended.

Adolescent↗