[How effective is mammography screening?].
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Biomedical subjects
Publications and source records attributed to G Wiedemann.
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The heat-induced interdependent changes of tumor blood flow, pO2, and pH decisively influence the therapeutic effect of hyperthermia (HT). This fact has induced us to determine simultaneously the frequency distribution of local pO2 values and the intratumoral pH in a xenotransplanted human sarcoma cell line at a normal blood glucose level and under hyperglycemic conditions before, during, and after HT. Two groups, one of 10 and one of 9 congenitally athymic nude rats with a subcutaneously implanted S117 human sarcoma into the right hind paw (mean tumor volume 5.3 cm3) were treated with local waterbath HT (tumor temperature 43 degrees C, 1 hr) alone or in combination with i.p. glucose injections (6 g/kg, 2 hr before the onset of HT). Tumor oxygenation remained improved throughout HT. Tumor pH did not decrease during HT. Hyperglycemia alone elicited a decrease of intratumoral pH and pO2, probably mainly due to hemoconcentration. The additional warming of the tumors (43 degrees C) during hyperglycaemia did not further decrease pO2 and pH. Silver stained sections of the tumors showed only a few very small necrotic areas, even in tumors of volumes up to 8 cm3. Our results indicate a well oxygenated tumor. In contrast to most tumors studied so far, hyperthermia in this tumor induces not only an initial increase of oxygenation but a lasting elevation of mean tumor pO2 for the duration of HT (up to 60 min).
The question as to whether the serum concentration of erythropoietin is relatively high for the degree of anemia in patients with erythrocytic hypoplasia has regained interest, since recombinant human-like erythropoietin has become available as a drug for replacement therapy. We have compared the concentration of serum immunoreactive erythropoietin in nonrenal anemic patients with erythrocytic hypoplasia (22 cases) or active erythropoiesis (82 cases). In both groups a negative correlation was determined between the blood hemoglobin concentration and the logarithm of the erythropoietin concentration. However, the two regression lines were not identical, and the serum erythropoietin concentration was significantly higher for the degree of anemia in the patients with erythrocytic hypoplasia. Additional measurements in four patients suffering from acute leukemia with marrow failure showed that the erythropoietin concentration decreased towards the values observed in anemic patients with active erythropoiesis when the erythron recovered in the early phase of complete remission. These data support the idea that, independent of the O2 offer, the proliferating erythrocytic progenitors by negative feedback lower the blood level of erythropoietin.
This article briefly describes the use of a photon counting system (ARGUS-100) in the detection of low levels of light. The ARGUS-100 was used in determining ATP in cell sections from tumor tissues and in measuring a luminescence-enhanced immunoluminometric assay, using ferritin as the analyte, based on the luminol-peroxide-4-iodophenol reaction with peroxidase as the enzyme. The aim is not so much the presentation of data, but rather to show the potentials of the photon counting camera in increasing our knowledge of the cellular and subcellular levels, as well as lowering the detection limits in already sensitive systems, such as immunoassays.
The dependence of the serum erythropoietin (Epo) level on the blood hemoglobin concentration was compared in patients suffering from leukemia and ulcerative colitis. In leukemia, the level of immunoreactive and bioactive Epo was generally much higher than in ulcerative colitis at comparable degrees of anemia. The highest Epo values were found in patients with severe bone marrow insufficiency of erythropoiesis. These findings support the hypothesis that the plasma level of Epo depends not only on the hemoglobin concentration of the blood but is also influenced by the proliferative activity of the erythron.
Thirty-one pediatric patients with brain tumors--25 primarily diagnosed, 6 recurrences--underwent MR and CT examinations before and after application of contrast media. Tumor detection, delineation of the tumor extent and definition of the tumor type were compared. Gd-DTPA-enhanced MR was superior in delineating the extent of primarily diagnosed tumors, which showed enhancement (n = 22). The tumor detection (1/6) and the identification of the tumor margins (5/6) were improved by Gd-DTPA in the 6 recurrences. Tumors without enhancement (n = 3) were judged by T2-weighted images better than by CT. The results suggest that Gd-DTPA is indicated for the evaluation of brain tumors in pediatric patients as well, especially since it offers advantages distinguishing between tumor types. Only the detection of tumor calcifications, which is rarely specific, is not possible by MR.
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In healthy children plasma ammonia concentrations show values from 12.3 to 57.2 mumol/l (80%-range) (group I). We also measured plasma ammonia in epilepsy patients with valproate therapy (group II) and epilepsy patients treated with other anticonvulsiva (group III). In a fourth group there were children with various cerebral lesions without episodes and without anticonvulsiva therapy. There were significant differences between group I and group II and group II and group IV respectively. But no significant differences were found between the patients who were treated with valproate and the patients with cerebral lesions. The data does not allow the plasma ammonia concentration to be taken as a control parameter in children treated with valproate. Ammonia estimation at the beginning of therapy, however, may be used as risk indicator.
Knowledge of the endogenous blood level of erythropoietin (Epo) has gained recent interest in view of the advances in Epo replacement therapy in anemic patients. By radioimmunoassay, we have carried out comparative measurements of the serum Epo level in patients suffering from chronic enterocolitis or leukemia. In chronic enterocolitis, the Epo level showed an exponential increase with the degree of anemia (up to 250 U Epo/1 serum at 70 g hemoglobin/1 blood). Similarly anemic patients with leukemia and severe bone marrow insufficiency of erythropoiesis had much higher Epo levels (usually above 500 U/1). Our findings indicate that the level of Epo is not only dependent on the blood hemoglobin concentration but also on the type of anemia. In fact, additional in vitro studies showed that immunomodulatory peptides can significantly influence the production of Epo in the hepatoma cell culture HepG2.
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We report two patients with thrombotic thrombocytopenic purpura who were subjected to plasma exchange. In one case, the plasma levels of platelet factor 4, measured shortly after plasma exchange, increased significantly during plasma exchange. This was followed, however, by a failure to respond to therapy. Repeated plasmapheresis over 3 weeks gave no therapeutic benefit and reversible deep coma occurred. This patient recovered completely after treatment with vincristine. In the second patient, a decline in platelet factor 4 was observed after plasma exchange. This was accompanied by improvement of the patient's condition and a slow rise in platelet count. Plasma exchange was again carried out in this patient because of a recurrence of thrombotic thrombocytopenic purpura 3 years later; again decreased platelet factor 4 plasma levels were observed after plasma exchange and again a therapeutic response followed. Platelet factor 4, therefore, seems to be an effective and early index for the therapeutic benefit of plasma exchange in thrombotic thrombocytopenic purpura.
Labelling index after one or repeated intravenous injections of 3H-thymidine was measured for various subpopulations of lymphatic cells in different canine lymphoid compartments and correlated with cell morphology. High doses of tritiated thymidine were injected and exposure times of up to 211 days were used. The labelling indices of lymphoid blasts were comparable in all tissues investigated. Labelling index varied from 100% in immunoblasts to 4% in small-sized lymphocytes. Approximately 80% of immunoblasts were labelled 1 h after 3H-thymidine application and 100% labelling was obtained after 12 h repetitive 3H-thymidine labelling. In contrast with medium-sized and large lymphocytes, immunoblasts seem to be rapidly proliferating cells in the dog with almost no Go cells.
The erythropoietin level was measured, by bioassay in polycythaemic mice, in the serum of anaemic patients suffering from different types of leukaemia. Comparative measurements were carried out in patients with ulcerative colitis. Serum erythropoietin was less well-correlated with the haemoglobin concentration in leukaemia than in ulcerative colitis. While serum erythropoietin did not exceed 200 mU/ml in patients with ulcerative colitis (lowest blood haemoglobin concentration 56 g/l), several of the leukaemic patients had serum erythropoietin levels above 500 mU/ml at comparable degrees of anaemia. Bone marrow biopsy showed that erythropoiesis was severely impaired in the leukaemic patients whose erythropoietin values were relatively high. These findings are in accord with the hypothesis that the plasma level of erythropoietin depends not only on the haemoglobin concentration of the blood but also on the bone marrow responsiveness to the hormone.
An evaluation of the HbF-content and the oxygen-half-saturation value took place in 15 newborn infants before, during and after an exchange transfusion. The initial HbF content decreased to 25% after the exchange transfusion with ACF-blood. The p50-value did not increase, as expected, but decreased dependent on the volume of the exchanged blood, caused by a quick loss of 2.3.-DPG in the ACD-blood within the first two days of storage. A normalization could be demonstrated 24 hours after the transfusion.
When clinical evidence provides grounds for suspecting inborn errors of metabolism it is urgent to perform the necessary, relevant, specific laboratory investigations in good time and with a view to quality. Normally, the realization depends on individual initiatives and the use of laboratories mainly designed for pediatrics and human genetics. Consequently the results are equally a matter of chance. Nothing in this situation can be changed in principle by using the catalogue of services of the Society for Human Genetics of the GDR. Central administrative provisions are necessary to improve the present unsatisfactory situation. Proposals for regulations, division of responsibility and a graduated programme of parameters are discussed here with a view to establishing uniform procedures.
Isoenzymes of creatine kinase (CK-MM and CK-BB) of samples of tissues from human skeletal muscle and human brain tissues were highly purified. Anti-CK-M and anti-CK-B were prepared by immunization of goats. The obtained antibodies were used in a modified immunoprecipitation method for measuring the creatine kinase subunits of CK-M and CK-B in serum.
We report three patients with advanced breast cancer who received hyperthermia (43 degrees C over 1 h, weekly x 4) and radiotherapy as palliative treatment for chest-wall recurrence. The case reports demonstrate situations where hyperthermia may be beneficial. These include tumours where radiotherapy alone is not expected to achieve control, such as large fungating tumours, and in previously irradiated areas. In these patients, hyperthermia with radiation achieves better local control of the tumour and delays the need for systemic chemotherapy. This may improve the quality of palliation.