Biomedical subjects
Publications and source records attributed to R Bauer.
The normal anatomy of the heart and the neighboring large vessels of a healthy volunteer is depicted in ECG-triggered NMR tomograms. The tomograms were recorded with a slice thickness of 10 mm without gap in transversal, sagittal and coronal orientation. They show a variety of anatomical and morphological details which cannot be obtained by means of other noninvasive imaging modalities.
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The search for the source of intraabdominal bleeding in the small intestine from Treitz' ligament to Bauhin's valve and in the large intestine up to the left flexure provides major difficulties: On the one hand angiographic examinations often were disappointing, on the other hand emergency endoscopy without time-consuming preparations is impossible. Therefore 14 patients during the period of January 1981 till September 1982 were examined with nuclear medicine in order to detect the localization of previously unidentified intestinal hemorrhage. The examination is conducted with the patient's own erythrocytes marked with technetium and requires comparison of early and late scintigraphies. The actual process of in-vitro tracing can be performed rapidly. In case the hemorrhage has stopped at the time of this examination, a later-date scintigraphy is possible without renewed injection up to 12 hours later. In 14 patients examined this way, the localization of hemorrhage could be identified in 50%. The 7 patients without recognizable source of hemorrhage showed no persistency of bleeding later on. The nuclear medical examination for identification of unknown intraabdominal hemorrhage does not burden the patient and requires no preparation. Therefore this technique serves as a valuable expansion to the existing range of diagnostic tools.
Heart function can be investigated non-invasively and without risk for the patient by means of radionuclide ventriculography. Coronary artery disease can be diagnosed with high sensitivity and distinguished from other diseases of the heart with high specificity by typical alterations of heart function as seen in rest and/or exercise scans. The hemodynamic significance of invasively proven stenoses of coronary arteries can de demonstrated and the function and functional capacity of surviving vital myocardium after myocardial infarction can be quantified scintigraphically. The efficacy of medical and surgical therapy can be documented and the course of disease can be followed up.
In a retrospective study of 728 patients with breast cancer up to 3 years after primary treatment skeletal scintigraphy yielded 15.8% (n = 115) bone metastases. By scintigraphic differentiation between a typical and an untypical pattern of bone metastasis a diagnostic accuracy of 99% was found. Depending on the local stage of tumor the rate of osseous metastases rises with increasing tumor size and with the extent of metastatic involvement of the lymph nodes. The frequency of bone metastasis proved to be also dependent on the histological type of tumor; it was highest in scirrhous carcinomas. By evaluating the scintigraphic behaviour of skeletal metastases under treatment in 122 patients we revealed an obvious decrease of metastatic deposits or complete normalization in 11.5% (n = 14), an unchanged finding in 32% (n = 39) and a progression of metastasis in 56.5% (n = 69). Therefore scintigraphic bone imaging in follow-up of breast cancer can be recommended for early detection of osseous metastases and for assessing the response of skeletal metastases to treatment.
Microelectrode penetrations nearly normal to the layers of foveal striate cortex in awake, behaving monkeys reveal a shift in orientation preference between cells in the upper and lower layers. Mean shift size for 57 penetrations is 54.8 degrees, with 70% of the penetrations showing shifts of 45-90 degrees. Marking lesions localize the shift to the border between layers 4C and 5. The data are suggestive of inhibition between the upper and lower layers within an "orientation column".
Red blood cells (RBC) were labeled with 99mTc in vitro after in vivo pretreatment with a stannous solution. The whole in vivo/in vitro procedure took 30-40 min. Pretinning was carried out by injection of either 6 mg DTPA and 0.6 mg Sn++ (Sn-DTPA) or 5 mg pyrophosphate and 0.7 mg Sn++ (Sn-PYP). The results of 1,356 patients were evaluated. The labeling yield was 89.7% (mean) after pretinning with Sn-DTPA and 88.2% following Sn-PYP pretreatment, the median values being 94% and 92%, respectively. The new method was successfully used in over 2,000 patients who had a radionuclide-ventriculography and in 38 patients studied for localization of occult gastrointestinal bleeding. Adverse side effects have never been observed.
On the postlateral gyrus of the cat striate cortex the cells' preferred orientation and the location of their receptive fields was measured as a function of cortical depth in penetrations as parallel as possible to the radiating fibres. In most penetrations the majority of infragranular cells showed orientation preferences 45 degrees-90 degrees different from the preferred orientations of supragranular cells. In addition, aggregate receptive fields from the same eye of supra- and infragranular cells were spatially shifted against each other. Using different columnar models these results are discussed in terms of spatial contrast enhancement for two parallel mechanisms in upper and lower layers, determined for pattern discrimination and movement detection.
A method for the preparation of 123I iodinated omega-phenyl-pentadecanoic acid (PPA) and a two-step separation of the o- and p-isomers is described. 98% pure p-iodophenyl-pentadecanoic acid is obtained within 3 h.
Biodistribution, plasma clearance and urinary excretion of omega-[p-123I-phenyl]-pentadecanoic acid were investigated in rats. The affinity of this radiopharmaceutical to red blood cells and to the plasma proteins was determined in vitro. Various radioactive metabolites were analysed by paper electrophoresis both in blood and urine at various intervals after administration of the compound. Protein-binding in plasma was determined by both electrophoresis and TCA precipitation. In vitro studies showed 30% uptake by red blood cells at equilibrium (30 min post-injection). 48% of the activity in the red cells could be removed after repeated washing with saline. The maximum uptake by myocardium occurred at 1 min and the maximal heart-to-blood ratios at 3 min. Although in vitro protein-binding was high, in vivo studies showed a very rapid plasma clearance (94% in 3 min) which indicated a weak binding. The amount of free iodine in plasma was less than 1% at any time after injection, thus not presenting a background problem or unnecessary radiation dose to thyroid and whole body. The major radioactive metabolites were 123I-p-hippuric acid and 123I-p-benzoic acid. In urine 123I-p-hippuric acid was excreted almost quantitatively. The metabolism was very fast, even 3 min post-injection the first metabolites could be found in the blood stream. Urinary excretion did not reach a plateau until 48 h. The total amount of radioactivity excreted was 56% within 48 h.
Oral retinoids obviously influence dermal components such as cutaneous capillaries and dermal inflammatory cells in addition to their well-known action on keratinizing epithelia. On this basis, they act as an anti-inflammatory drug. In particular, they reduce the elevated skin temperature, inhibit the motility of neutrophils and eosinophils and their migration into the epidermis, decrease DNA synthesis of human lymphocytes by blocking their response to lectins and stimulate Langerhans cells, monocytes and macrophages in various in vitro and in vivo models. These data indicate that oral retinoids may not only normalize disorders of keratinization but also exert distinct therapeutic effects on various skin diseases with dermal inflammatory involvement regardless of their particular aetiology. In some respects, retinoids resemble corticosteroids, acting as a modified hormone. Preliminary clinical experiences with oral retinoid treatment in skin diseases such as cutaneous disseminated LE, bullous pemphigoid, Duhring's disease, pemphigus, Behçet's disease and necrotizing vasculitis with eosinophilia support these data. Monotherapy or combined administration of oral retinoids with corticosteroids in low doses seems therapeutically beneficial in these disorders.
Pemphigus herpetiformis is an unusual variant of the pemphigus group, showing acantholytic bulla formation together with marked eosinophilic spongiosis. The clinical picture shows erythematous and pruritic papulovesicular bullous lesions affecting the skin and the oral mucosa. It most closely resembles dermatitis herpetiformis or bullous pemphigoid. In contrast, the presence of acantholysis and of antiepithelial antibodies indicate pemphigus. Three patients, all women, showing this unusual variant of pemphigus, were seen during the last 3 years, a fourth is reported here. One patient responded well to dapsone; the three others did not. Oral treatment with aromatic retinoid (Ro 10-9359) was clearly effective in the last patient, leading to full remission of the skin lesions in a few days. The oral mucosa improved only partly. Discontinuation of the aromatic retinoid treatment and replacement of the drug by placebo was followed by a relapse both of mucosal and skin lesions. Aromatic retinoid possibly inhibits eosinophilic migration into the epidermis and impedes acantholysis associated with this phenomenon.
This is a report on a young homosexual US citizen with disseminated Kaposi's sarcoma of the skin who has lived in Berlin for about 1 year. During the last few years this malignant variant of the conventional Kaposi's sarcoma-characterized by rapid generalization and aggressive course--has become epidemic in some big cities in the USA. Until now there exist only a few reports from Europe. The data of our patient are representative of the typical epidemiologic, anamnestic, clinical, and diagnostic features of this unusual disease. Acquired immunodeficiency, high frequency of infections, and drug abuse may represent major etiologic factors. This report underlines the possibility that the disseminated type of Kaposi's sarcoma in young men may be observed more often in Europe in the near future.
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The influence of the aromatic retinoid Ro 10-9359 on the migration of neutrophilic granulocytes was examined in standardized supravital preparation. For this purpose, leukocytes were taken from 5 psoriasis patients who had been treated with 75 mg of aromatic retinoid for 3 weeks. The examinations showed that the course of granulocyte migration was disturbed: the dormant stage was prolonged up to several hours. Maximum cell motility was already reached in that stage of motion in which the granulocytes maintained a constantly changing and bizarre cell pattern. The migration stage, which is characterized by a directed linear cell movement, was absent. Leukocyte survival time was shortened by 50%, and cell degeneration was abnormal under the influence of the aromatic retinoid.
A complete staging of immunity in lupus erythematosus includes immunoserologic, immunocytologic, and immunohistologic findings. However, not all of these laboratory findings are of clinical relevance. The most important immunologic parameters for lupus erythematosus can be summed up in three obligatory and two facultative tests. This "immunologic staging" is considered to be of decisive importance for the risk classification of patients with lupus erythematosus and for the choice of the therapeutic procedure.