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Biomedical subjects

S Ulrych

Publications and source records attributed to S Ulrych.

17 recordsLinked to original sources
PubMed1988

Trends in exploitation of packed red blood cells.

The following trends aim to a more efficient exploitation of packed red blood cells (PRBC): 1. Improvement of the operative distribution of PRBCs for transfusions before expiration. 2. Prolongation of the expiration time by monitoring the biochemical and physical processes during banking. Maintenance of native hemoglobin and restoration or substitution of substances involved in transport of energy and of oxygen are of utmost importance. Enzymic conversion of RBCs of blood group A, B to 0 is not supposed to leave laboratory scale soon. While cryo-conservation of RBCs with glycerine is known, freeze-drying of PRBCs remains a speculation. 3. Use of PRBCs after expiration as a raw material for products applicable in medicine and biochemistry. Stroma-free hemoglobin variants (SFH) are known as effective infusable oxygen carriers in experimental animal models. However, there is little convincing evidence on the metabolism and innocuity of SFH variants in human organism. Therefore, systemic infusion of SFH solutions is not yet acceptable to clinicians even in emergency situations. On the other hand, a broader use of SFH and its variants is anticipated and regarded as prospective in organ perfusion, cardioplegy and transplantation as well as in analytical biochemistry.

Blood Banks↗
PubMed1985

Haemoglobin lyophilized with sucrose: the effect of residual moisture on storage.

Sucrose is one of the most effective substances which protect haemoglobin from spontaneous methaemoglobin formation during lyophilization and subsequent storage. The dry haemoglobin-sucrose system was treated under different conditions of temperature (up to 85 degrees C), time of storage (up to 6 years) and residual moisture (less than 0.1-7.5% H2O), in order to reveal the main features of the hitherto unclear mechanisms of both spontaneous methaemoglobin formation and of the stabilizing effect of sucrose. In conclusion, a dry sucrose network was recognized as a significant support to the native ferrous structure of oxyhaemoglobin, while the presence of water molecules, of assumed peroxidic radicals and the action of thermal vibrations favour the oxidation and denaturation of haemoglobin.

Blood Preservation↗
PubMed1976

Stroma-free haemoglobin solution for infusion: changes during storage.

The stability of experimental haemoglobin solution for infusion (HSI) was investigated during one year storage at temperatures 20 degrees to 25 degrees C, 4 degrees C, -8 degrees to -12 degrees C, and -195.8 degrees C, respectively. Main attention was devoted to the formation of precipitate, oxidation to haemiglobin and general changes in the absorption spectrum between 550 and 650 nm. Changes were almost negligible in HSI samples stored in the frozen state. This procedure now seems the most feasible to keep the HSI injectable for at least one year. Storage at 4 degrees C led to a marked increase of haemiglobin and to changes of the absorption spectrum. Storage at 20 degrees to 25 degrees C caused profound changes of all parameters tested. Addition of EDTA, ascorbic acid or glutathione, or storage in N2 atmosphere under the given conditions failed to increase the stability of HSI. Storage of HSI samples at pH values between 7.0 and 7.8 led to similar results.

Ascorbic Acid↗