Biomedical subjects
Publications and source records attributed to P Fischer.
The introduction of digital subtraction angiography for the investigation of heart disease has lead to improved image contrast, with a marked reduction in radiation to patients, as compared with conventional radiography. Indications for ECG-triggered computed tomography of the heart in women should be strictly limited.
The mutant strain ACN of Pseudomonas aureofaciens ATCC 15926 produces several bromo derivatives of pyrrolnitrin. Five brominated amino- and three brominated nitrophenyl pyrrole compounds could be isolated, and their structures were established by 1H NMR, UV and mass spectroscopy. The isolated amino compounds showed no biological activity; the nitro derivatives inhibited the growth of Neurospora crassa ATCC 9276, though not as effective as pyrrolnitrin itself. 2-Carboxy-4-(2-amino-3-bromophenyl)pyrrole (X) is demonstrated to be an intermediate in the biosynthesis of brominated pyrrolnitrin; the biosynthetic pathway to bromo derivatives of pyrrolnitrin is discussed.
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To detect karyotype changes during the chronic phase of CML, 31 mostly Ph1-positive patients were followed cytogenetically over a period of 3 years. Newly emerging abnormalities, e.g. second Ph1-chromosome, iso17q, trisomy 8, could be correlated with clinical and hematological characteristics of the course of the disease if they constituted the first additional chromosomal change. In 54 patients with suspected or established blast crisis, TdT determinations were performed. Out of 27 patients with verified blast crisis, 6 showed markedly elevated enzyme activities in the leukemic blast cells. These patients proved to be very sensitive to cytostatic therapy with prednisone and vincristine. The continuous observation of TdT levels enabled us to initiate a controlled and, with respect to the quality of life, a less toxic therapy. Our data indicate that serial chromosomal analyses and TdT determinations are of great value in predicting prognosis and therapeutic responsiveness in CML.
A new human plasmacytoma cell line (Karpas 707) has been established from a myeloma patient. The cultured cells are negative for Epstein-Barr viral nuclear antigen and free of mycoplasma. They are similar to plasma cells and secrete only lambda light chains. The cells are hypodiploid and contain the Philadelphia chromosome and other abnormalities. This cell line may be suitable for the production of human monoclonal antibodies.
25 Patients with metastatic non-seminomatous testicular neoplasms were treated by surgery and cytostatic therapy using a combination consisting of Velban, Bleomycin, Cis-Platinum and/or Ifosfamid. In 22 patients this procedure induced a persistant complete remission with a mean observation time of 23 months. 2 patients died because of post-surgical complications after a second-look-lymphadenectomy. They suffered from rapidly progressive tumor disease. One patient died in a septicemia during chemotherapy. Our experience is that morbidity of an effective chemotherapy should not be underestimated. Transient bone marrow suppression, anorexia, alopecia and hyperpigmentation are unavoidable. However, severe vomiting, disturbed electrolyte metabolism, hemorrhagic cystitis, anemia and septicemia can well be managed by respective supportive care. Septicemia, for instance, may be treated with appropriate antibiotics without inducing tubular necrosis. Supportive measures also will avoid severe chronic defects of ear and kidney function.
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A large number of human haematopoietic cell lines was examined for spontaneous production of interferon. Unconcentrated culture supernatants from 70 out of 71 B-lymphoblastoid cell lines contained considerable amounts of interferon (median titer 22 units per ml); a few lines produced more than 100 units/ml with peak values up to 500 units/ml. In contrast, only one B-lymphoma line out of 18 genuine lymphoma, myeloma, and leukaemia cell lines tested spontaneously produced small amounts of interferon. Following treatment with 5-bromodeoxyuridine (BrdUrd), interferon was produced without further induction in most B-lymphoid cell lines, but not in any of the non-B, non-T, T-lymphoid or myeloid lines examined. Modulation of spontaneous interferon production by chemicals (sodium butyrate, dexamethasone, dimethylsulfoxide, a phorbol ester, and BrdUrd) was studied in more detail in three B-lymphoblastoid and four B-lymphoma cell lines. The patterns of responses observed were different for the action of different chemicals on a given cell line as well as between lymphoblastoid and lymphoma lines in general; furthermore, several lines of evidence suggest that chemicals can differentially influence spontaneous and virus-induced interferon production in an given cell line. The composition of spontaneously produced interferon was analysed using antisera specific for HuIFN-alpha and HuIFN-beta. Interferons produced by untreated as well as BrdUrd-treated lymphoblastoid cells contained more than 95 per cent IFN-alpha, whereas BrdUrd-treated lymphoma cells produced IFN-alpha as well as minor amounts (cell lines Namalwa and NC-37) or even over 90 per cent of IFN-beta (Daudi).
The results of an IAEA coordinated programme on radiation induced chromosomal aberrations in human peripheral blood lymphocytes in vitro are presented. In a master experiment, a whole blood sample from one donor was irradiated with 200 R of X-rays. Different fixation times from 46 to 82 h were used. The progression of cells into mitosis was monitored by BrdUrd incorporation. 14 investigators took part in the scoring of chromosomal aberrations. The main conclusions of this study are: (1) The mean frequencies of aberrations changed with fixation time. (2) The number of cells scored as aberrant by different laboratories was very similar, but there was variability in the number of aberrations scored per aberrant cell. (3) The differences in the frequencies of aberrations between laboratories were minimal when the scoring was restricted to the first major peak of mitotic activity and sufficient cells were scored. It is concluded that using controlled experimentals conditions, human peripheral blood lymphocytes can effectively be used as a reliable biological dosimeter for absorbed radiation dose.
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In five children and one adolescent biopsies of the septal cartilage partially covered with inner perichondrium, were removed during septoplasty and buried into the retroauricular region for 1.8 to 5.3 years. After removal the implants were equal or reduced size. Histologically the cartilage showed its original structure in three children who were before their puberal growth spurt at the time of the removal of the implant. In the other three who were beyond this growth spurt the septal cartilage was partially or nearly totally ossified. The presence of the innermost perichondrium may prevent resorption of the cartilage. At the borders of the cartilage without perichondrium signs of resorption were more marked in the elder group than in the younger.
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