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Biomedical subjects

S Preussner

Publications and source records attributed to S Preussner.

At least 19 recordsLinked to original sources

[Hemorheological/hemodynamic study on miniaturized capillary filters in the concept of an implantable artificial kidney].

The conception of an implantable kidney provides the substitute of the non-functioning kidney by a technical-biological system. The filtration function is to be performed by a capillary hemofilter. The results obtained in an open test circulation on 3 filters produced by optimum aspects were represented and compared with the physiological performance parameters of the kidney. The special importance of the construction of the flow conditions in the single capillary is accentuated as the fundamental aspect for additional optimization. An optimized capillary filter produced the necessary filtration rate for maintaining the homeostasis on condition of a low-protein diet and an increased level of blood urea. The changes of the hemorheologic parameters is to come up by an adequate absorption of fluid in the colon.

Capillaries↗

[Thrombocyte substitution, 2: Thrombocyte preparations and determining the effectiveness of thrombocyte transfusion].

The success of a transfusion of thrombocytes is influenced by numerous factors concerning both the preparation of the platelet concentrate and the recipient. In a long-term substitution of thrombocytes on account of the appearance of immunological and unspecific consumption processes the control of the effectiveness is indicated. The determination of the thrombocyte increment and the resonance thrombography are suitable for this purpose. Fever, sepsis, splenomegaly and haemorrhage cause a diminution of the increase of thrombocytes after transfusion. Isoantibodies have the greatest influence on the shortening of the survival time of transfused thrombocytes. The corrected increase of thrombocytes (CI) 1 hour after the transfusion is lowered under 5.0 Gpt/l (m2). Directives are given for the transfusion and statement of the success of thrombocyte concentrate in patients with leukaemia and malignant tumours.

Blood Transfusion↗

[Thrombocyte substitution. I. Indications and clinical use of thrombocyte transfusion].

The clinical use of the transfusion of thrombocytes, its indication and problems in the long-term substitution of thrombocytes are explained. Out of the side effects the alloimmunisation against antigens of the HLA-system in the long-term substitution is of greatest importance. A substitution of thrombocytes is indicated in the disturbances of formation. The substitution shall be performed prophylactically in the acute leukaemia and aplasing therapy. When an increased destruction of thrombocytes is existing, other therapy principles are important. Recommendations are given for the prophylactic substitution of thrombocytes. The analysis of the transfusion of 320 concentrates of thrombocytes is reported.

Blood Grouping and Crossmatching↗

[The effect of the cell separation procedure on neutrophilic granulocyte function. I. Research on the morphology and phagocytosis behavior of isolated granulocytes].

The investigations were aimed at detecting the impact of various cell separating techniques on the morphology and function of neutrophilic granulocytes. Methodically simple cell separating techniques were used, such as spontaneous sedimentation of ACD-AG blood and mechanically defibrinated blood and a flotation technique which makes use of cell isolation by means of a separating solution and centrifugation. Granulocytes which were isolated by the cell separator Haemonetics M 30 for therapeutic purposes and which, according to data in literature, are not damaged by cell separating techniques were used as reference cells. The electronic-optical evaluation of granulocyte morphology and the in vitro investigation of the phagocytic capacity for rice starch (ingestion rate) of differently isolated granulocytes were made after cell separation.

Cell Separation↗

[The effect of the cell separation procedure on neutrophilic granulocyte function. II. Research on the bactericidal capacity and the NBT reduction ability of isolated granulocytes].

The investigations were aimed at examining the impact of methodically simple separating and enriching techniques for gaining granulocytes on the bactericidal capacity and NBT reduction in isolated granulocytes. For this purpose, granulocytes were gained by the technique of sedimentation and flotation. Granulocytes isolated by the cell separator Haemonetics model 30 were used as reference material. The findings of the investigations together with those of previous studies revealed no indication of the granulocyte function and morphology being damaged by the separating techniques used.

Blood Bactericidal Activity↗

[The function of granulocytes stored in whole blood in relation to the storage time].

Whereas numerous investigations and extensive experiences have been available for some years on problems of storing erythrocytes and thrombocytes, it was only recently that the storage of granulocytes with the aim at maintaining their function for a longer period has been given proper regard as a problem, which, however, could not be brought to a satisfactory solution. Primarily, attention is focused on specific cell physiology. At the same time it is necessary to have at hand a number of approaches covering as many partial aspects of the granulocyte function as possible to identify the functional damages or the extent of cell damage in connection with storage. In the present paper the behaviour of granulocytes under conditions commonly used in transfusion medicine for storing blood are investigated for a period of 4 days by controlling the total leukocyte and granulocyte values, pH value, osmolality, vitality test in the colour excluding test as well as by function tests such as behaviour of phagocytosis and NBT capability of reduction. A report is presented on the results of quantitative and qualitative changes in the investigated parameters.

Blood Physiological Phenomena↗

Relation between reduced electrophoretic mobility of human lymphocytes and the inhibition of spreading of human monocytes caused by the same anti-human lymphocyte globulin.

Slowing of electrophoretic mobility of human peripheral blood lymphocytes after adding anti-human lymphocyte globulin (AHLG) in vitro correlated with indices of the monocyte spreading inhibition obtained by the same AHLG. Consequently, electrophoretic results may be associated with the prolongation of skin allograft survival in primates - the best and the only practical in vivo test for determination of the immunosuppressive potency of AHLG. If so, the simple electrophoretic test could be used in combination with other in vitro tests, preferably for monitoring of the AHLG production.

Antilymphocyte Serum↗

The in vitro effect of horse anti-human lymphocyte globulin on the electrophoretic mobility of human lymphocytes and platelets.

In accordance with earlier results the electrophoretic mobility of lymphocytes is decreased by horse anti-human lymphocyte globulin (AHLG), which correlates with the results of the rosette inhibition test. Under the influence of AHLG, the distribution of the electrophoretic mobilities of lymphocytes shows a characteristic change. In some of the AHLG samples, the antilymphocyte action is accompanied by an antithrombocyte effect. The resulting decrease in the electrophoretic mobility of platelets correlates with the thrombocytopenic effect in vivo. The variation of pH or ionic strength leads to changes of the AHLG effects. The in vivo influence of AHLG on the distribution of the electrophoretic mobility of peripheral blood lymphocytes and platelets is discussed.

Animals↗

A simple method in investigating anti-human lymphocyte globulin.

The methods involves the influence of AHLG on the electrophoretic mobility of platelets and lymphocytes. There is a close correlation between the electrophoretic inhibitory effect of AHLG on platelets and the thrombocytopenic AHLG effect in vivo, so that method can be used for evaluating the unwanted AHLG side-effects on platelets.

Antilymphocyte Serum↗

[Compatibility of antihuman lymphocyte globulin (AHLG). Possible side effects and complications].

The results in the antihuman lymphocytic globulines (AHLG) therapy of 25 patients with predominantly haematological and neurological diseases are reported. Extent and scope of the side-effects observed are discussed. A careful clinical, clinico-chemical and immunological observation of the patients during the AHLG therapy is indispensable for performing this biological immunosuppression and a strict selection of patients is also required. Under these conditions there are no higher risk and responsibility in an AHLG therapy than in other intensive kinds of therapy.

Anemia, Hemolytic, Autoimmune↗

[Use of antilymphocyte globulin in autoimmune nervous system diseases].

The pathogenetic bases for the indication of immunosuppression in multiple sclerosis are represented in a survey, rested upon experiences in the clinical compatability test of AHLG Dessau. The knowledge gained in animal experiments and epidemiology in recent years is considered and problems of membrane, slow-virus hypothesis, genetic problems and changes of immunoglobulins and lymphocytes are critically referred to.

Antibodies, Viral↗

[Granulocyte kinetics with radioactive diisopropylfluorophosphate (DF32P) and radiochrome (51Cr)].

Determining granulocyte kinetics with DF32P allows various parameters to be gained during the in-vitro marking, such as the total blood granulocyte pool, circulating granulocyte pool, marginal granulocyte pool, daily granulocyte exchange rate and half decay period of granulocytes. The half decay period of granulocytes, bone-marrow reserve in myelocytes, metamyelocytes and band cells as well as polymorphonuclear neutrophils can be determined by in-vitro marking, with DF32P being intravenously injected. The combination of both procedures with DF32P will reveal the half decay period, pool sizes and exchange rates of the proliferating myelocyte compartiment in bone-marrow and mature blood granulocytes. If 51Cr is used for determining granulocyte kinetics the surface activities of various organs, such as heart, liver, spleen, and lungs, can mainly be determined in addition to the half-life of leucocytes, indicating the degradation or storage of cells in certain areas of the body. In addition to normal values those findings are principally presented which were obtained with in-vitro marking by DF32P and 51Cr in chronic myeloid leukaemia, osteomyelofibrosis or osteomyelosclerosis respectively and in hypersplenism.

Cell Survival↗

[State and development of liquid conservation of thrombocytes].

In the present investigation the storage effect of AcD-AG and CPD-AG-stabilizers on thrombocytes was tested. The platelets were stored in platelet-rich plasma (PRP) at 4 degrees C or room temperature for 3 days. The concentrates gained by it were marked with Na251CrO4 and reinjected. The thrombocytokinetic parameters were evaluated. The results show that storage with the help of the mentioned stabilizers can be made to a certain extent only. Platelets stored in AcD-AG stabilizerhad a survival time of 2.7 +/- 1.1 days towards 9.0 +/- 1.0 days of fresh whole blood concentrates. The survival time of CPD-AG thrombocytes stored at 4 degrees C for 3 days amounted to 2.0 +/- 0.5 days. Storage of CPD-AG platelets at room temperature showed favourable results. Their survival time amounted to 6.2 +/- 0.6 days. Measurements of surface activity above the spleen and the liver indicate that degradation of stored platelets is mainly performed in the spleen. Problems of liquids storing in view of the significance of therapeutic thrombocyte substitution for hospitals are referred to.

Blood Cell Count↗

[Studies of thrombocyte function in CPD blood].

The CPD stabilizer according to Gibson with an addition of 1.25 mMol adeninesulfate and 2.50 mMol guanosine is used in blood storage for better preserving 2.3-bis-phosphoglycerate of erythrocytes. Here platelet-rich CPD plasma was investigated before and during a 3 days storage at 4 degrees C or room temperature with regard to preserving the global thrombocyte function. The latter consists in the ability to seal blood vessels and is tested by means of pressure registration in combined thrombocyte-aggregation-adhesion (DKTA method) as an ability to close the pores of a sieve by adding 10(-5) mM/l of ADP. At room temperature this thrombocyte function is approximately 0 following 3 days of storage in CPD plasma excess without shaking. When stored at 4 degrees C it is preserved to a slight degree. Loss of thrombocyte function will depend on pH, thus being particularly evident at room temperature.

Blood Platelets↗

[Mycological studies of patients with hemoblastoses].

40 patients with haemoblastosis were examined clinically and by cultures for presence of yeast mycosis. Moreover, we analyzed specific antibodies with the help of cell agglutination, the passive haemagglutination and the precipitation using Candida antigen. 29 test persons were found having a yeast mycosis, 3 patients without clinical symptoms in pharynx showed presence of yeasts by culture, 8 test persons were clinically and mycologically negative. In cell agglutination we recorded titres of less than 1:20 to 1:5 160 and in haemagglutination titres of less than 1:20 to 1:5 160 and in haemagglutination such of less than 1:20 to 1:320. 5 patients showed positive precipitation reaction with antigen extracted of membranes of Candida albicans cells. We observed different titre motions with these patients: during illness the titre either rised or decreased clearly, or the patients were in a condition of humoral anergy against the Candida albicans antigen. It is hinted at the necessity to watch over susceptible patients mycologically.

Acute Disease↗

[Use of nuclear-medicine technics in the differential diagnosis of anemias].

The use of nuclear-medical methods is especially described for the diagnostic of anaemias with different etiology. For the diagnosis of the chronic haemorrhagic anaemias the determination of the blood losses through the gastrointestinal tract with the help of the 51Cr-method and for the course of the acute haemorrhagic anaemias the automatized determination of the blood volume are emphasized. For the proof of a latent haemolysis often the knowledge of the apparant half survival time of the erythrocytes is necessary. Also in manifest haemolysis this investigation method gives differential-diagnostic references. For the megaloblastic anaemias a diagnostic routine programme and a differentiated investigation scheme are reported by Hoffbrand. For the clarification of the anaemias by insufficiency of the bone-marrow and ineffective erythropoiesis the radio-iron-kinetic investigations have proved. They should also be taken into consideration for the indication of the transplantation of the bone-marrow.

Anemia↗

[Iron-deficiency syndrome].

A short survey is given on iron deficiency, its pathophysiology, the causes, the clinical symptomatology and the therapeutic possibilities. On account of the abundance of the material only the most important facts could be treated. Hereby the clinical practice was particularly taken into consideration. Essential theoretical questions have been outlined only in short.

Anemia, Hypochromic↗