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Biomedical subjects

V Kretschmer

Publications and source records attributed to V Kretschmer.

At least 127 records · Page 7Linked to original sources
PubMed1989

Biocompatibility and safety of cytapheresis.

Cytaphereses are safe and can be used routinely like whole blood donations on the premise that standard techniques based on appropriate guidelines and regulations are performed. Before the introduction of a new cell or plasma separator, a thorough clinical investigation is always recommended in order to demonstrate biocompatibility and safety features. In this context cell loss and damage as well as activation of coagulation and complement should be tested primarily. The examination should consist of a direct comparison with an approved system. In addition, it is necessary to repeat periodically on multicenter studies adverse donor reactions such as those already described so that it is possible to recognize even rare side effects. Of special importance are long-term studies of donors undergoing frequent cytaphereses for many years in order to detect relevant immunological changes. On the other hand, harm caused by the plasticizer or cancer due to cancerogenicity of the plastics are only speculative at the moment.

Biocompatible Materials↗
PubMed1989

The influence of Romanowsky-Giemsa type of stains on the nuclear texture of desoxyribonuclease-treated cytological preparations.

It had been observed that cell films where DNA had been partially digested by DNase stained differentially by the standard RG stain and a representative commercial Giemsa mixture. The reasons for this divergence were experimentally investigated. The lower concentration of Azure B in the commercial Giemsa mixture as compared with the standard RG stain emerged as the most likely factor causing the divergence of staining behaviour. A correlation of this assumption to the theory of the RG stain is tentatively suggested.

Animals↗
PubMed1989

The influence of cationic thiazine dyes on eosin Y-uptake of red blood cells in Romanowsky-Giemsa type stains.

In the present study we have investigated the uptake of cationic thiazine dyes and of the anionic Eosin Y by red blood cells (RBCs). Blood smears were stained with Azure B-Eosin Y, Methylene Blue-Eosin Y, Thionin-Eosin Y and with the cationic and anionic dyes alone at varying concentrations. Dye content of erythrocytes was measured with a Vickers M 85a microdensitometer. Nuclear chromatin features of white blood cells were investigated with the IBAS 2000 image analyser. Azure B favoured Eosin Y uptake of RBCs remarkably, and vice versa. There was no clear indication of that type of molecular interaction which characterizes the generation of the colour purple on polyanions. Methylene Blue and Thionin left Eosin Y uptake unaffected, but contamination of the standard Azure B-Eosin Y stain with Methylene Blue obviously affected Azure B-Eosin Y uptake, probably by competition of Methylene Blue and Azure B binding in RBCs. Furthermore, Methylene Blue contamination of the standard stain increased the rate of error in image analysis of white blood cell nuclei due to variations of staining intensity. For cytophotometry and image analysis of blood smears the standard Azure B-Eosin Y stain is by far superior to the commercial stain which normally is contaminated with Methylene Blue and some of the lower azures.

Azure Stains↗
PubMed1989

[The status of blood coagulation preparations within the scope of modern hemotherapy in surgical patients].

The risks and adverse reactions of fresh frozen plasma (FFP) and coagulation components have changed considerably in the last few years because of the spread of HIV on the one hand, and advances in the preparation and sterilization of coagulation components on the other. Therefore, the indication for FFP and the various coagulation components deserves constant consideration; this is the intention of this paper. FFP is still the therapeutic choice for the treatment of acquired (complex) plasmatic coagulation disorders, even though the (still) small risk of virus transmission in Middle Europe has to be taken into account. Coagulation components are primarily indicated in congenital (isolated) plasmatic coagulation disorders. Only in gross or very acute acquired coagulation disorders are coagulation components needed in addition to FFP. The same regimen is recommended for the use of antithrombin III (AT III) concentrates. In cases of acquired antithrombin deficiency, antithrombin III substitution is indicated only when the anticoagulation by heparin alone or in combination with FFP is insufficient or when the heparin doses required might entail an unexceptable bleeding risk, e.g. in simultaneous thrombocytopenia. Then AT III becomes an important therapeutic factor, especially in DIC. In addition, information regarding a rational and economic substitution of FFP and coagulation components is given, and other substitutes are mentioned which could possibly be used with less risk. Finally, the necessity for an adequate diagnostic procedure is emphasized. Close cooperation between the physicians in the clinics and in the department of transfusion medicine/hemostaseology reduces unnecessary and inadequate application of coagulation components. This also means an improvement of the patient's therapy.

Blood Coagulation Disorders↗
PubMed1988

Victoria blue B--a nuclear stain for cytology. A cytophotometric study.

The aim of this study was to investigate the staining characteristics of Victoria Blue B in alcohol solutions. Cytological specimens (liver and spleen tissue imprints, blood smears) were stained with methanol solutions of commercially available Victoria Blue B-Cl and with pure Victoria Blue B-BF4. The dye concentration, staining time, and protone concentration of the dye solution were varied. The dye solutions were characterized using spectrophotometry and thin-layer chromatography. Cytophotometry and image analysis were used to quantitate the staining pattern of cell nuclei. Feulgen-stained slides were used as controls. Victoria Blue B-BF4 gave excellent nuclear staining exhibiting a quantitative dye-substrate relationship, whereas commercial dyes resulted in lower staining intensity and less distinct nuclear texture. Dye concentration and staining time were, over wide ranges, not of critical importance for the quality of the staining. Under certain staining conditions, only cell nuclei were stained, with the background remaining completely unstained. We presume that, in alcohol solutions, Victoria Blue dye binds as a neutral dye molecule in conjunction with its anion. Victoria Blue B-BF4 staining provides a simple and reproducible staining technique for cytology which is suitable for use in automated cell-pattern recognition.

Animals↗
PubMed1988

Improvement of blood component quality--automatic separation of blood components in a new bag system.

We report here on a new multiple bag system with top and bottom drainage of the primary bag which allows automatic separation of blood components on a routine basis. 100 units of 450 ml fresh whole blood (CPD) were centrifuged by hard spin centrifugation and then separated into leukocyte-poor red cell concentrates in additive solution (volume 284 +/- 22 ml, Hct 63.5 +/- 3.2%, platelets 3.1 +/- 1.4 X 10(9)/unit [3.1 +/- 1.2%], leukocytes 1.9 +/- 1.2 X 10(8) [8.3 +/- 5.0%]) and plasma (FFP) with acceptably low cell contamination (volume 262 +/- 33 ml, platelets 14.6 +/- 5.6 X 10(3)/microliter, leukocytes 0.04 +/- 0.03 X 10(3)/microliter). The residual buffy coat of whole blood stored for 16-20 h at room temperature was suitable for the preparation of leukocyte-poor platelet concentrates (n = 20; platelets 0.67 +/- 0.17 X 10(11) (69.8 +/- 15.0%); leukocytes 0.1 +/- 0.1 X 10(8] which showed quite good platelet function in vitro. The removal of leukocytes and platelets caused significantly less in vitro hemolysis during storage when compared to conventionally prepared red cell concentrates with and without buffy coat. Further advantages of the reduction of the cell contamination in red cell concentrates before storage are discussed. From this it can be concluded that leukocyte-poor red cell concentrates with less than 20% residual leukocytes should become the regular red cell preparation also for surgery, especially as the recommended separation technique can easily be performed on a routine basis. Red cell concentrates still containing the whole buffy coat are no longer acceptable.

Adenosine Triphosphate↗
PubMed1988

[Autologous blood donation].

Because of the risks and side reactions of homologous blood transfusion autologous blood donation/transfusion is always indicated when it is practicable. Appropriate performance has to be guaranteed. By adequate training of the responsible physicians drawing and storage of autologous blood as whole blood should be general possible. However, separation into buffy coat poor red cell concentrates and fresh frozen plasma (FFP) has clear advantages. Therefore the cooperation with a blood bank or a transfusion service should be intended to which production of blood components is restricted. There is an indication for autologous blood donation in all patients who plan to undergo an elective operation being cardially compensated without "hematogenous" infection and with at least 12 g/dl hemoglobin. The aptitude examination generally may be confined on history, physical examination including blood pressure and blood counting. In a preoperative interval of 2 to 28 days it is possible to reserve 1 to 4 units of whole blood or the same number of red cell concentrates and FFP when the patient has normal haematopoiesis. The greatest problems concern the organization. They are easily to be solved by adequate information of all persons involved and close cooperation between the various physicians sending the patient to the hospital, taking care of him in the clinic and drawing the autologous blood.

Blood Donors↗
PubMed1987

Side-effects and technical problems in cytapheresis with cell separators. Results of a retrospective multicenter study.

On the basis of a survey, the acute side-effects and technical problems in a total of 77,525 cytaphereses (IFC 36,530, CFC 40,995) in donors at 39 hemapheresis centers were retrospectively analysed statistically. In general, relevant donor side-effects (0.78%-1.05%) were more rare than the primary donor-independent disturbances (1.65%-2.63%). The donor side-effects predominated merely with the use of the cell separators Haemonetics M30/Belco (1.06% vs. 0.57%). These were mainly circulatory reactions (0.83%), which were generally much more frequent with IFC (0.54%) than with CFC (IBM/Cobe 0.11%, CS-3000 0.19%). Potentially fatal complications were not reported. The frequency of side-effects, disturbances and discontinuations correlated inversely with the separation rate of the individual centers per method. Centers in which two or three methods were applied simultaneously reported a higher frequency of side-effects and disturbances. Hemolysis was only observed with IFC (0.09%), but not with the use of the Haemonetics V50. The greater susceptibility to disturbances of technical/methodological/operational origin essentially results from the more elaborate, but not yet perfected technology, including computer control and monitoring, as well as defects in the production of the much more complicated disposable sets. Thus the highest rate of discontinuations was calculated for the system which is so far the most sophisticated technically (CS-3000, 1.85%). Although the primary donor-independent problems sometimes correlate directly with the manifestation of donor side-effects, the greater technological sophistication of automatically controlled and monitored systems cannot be dispensed with, since only in this way can potentially fatal risks for the donors be largely ruled out.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Component Removal↗
PubMed1987

The safety of and the strain on the donor during thrombocytapheresis on the cell separator. A psychological study.

The study deals with the question as to what extent and under which existing personal characteristics does thrombocytapheresis on the cell separator (Fenwal CS-3000) lead to psychological stress for the blood donor? A comparison is made with the stress experienced during the established 450 ml full-blood donation. Because of the different procedural conditions, it was postulated that the donation on the cell separator creates greater psychological stress than the established type of donation. To examine this hypothesis, a sample group of 76 cell-separator and full-blood donors were asked to complete a questionnaire concerning the stress they experienced and their attitude before, during, and after the donation. Their personalities were also examined. A control group of 45 full-blood donors was examined in the same way. No significant statistical difference was found regarding the extent of stress under both conditions of donation. These findings are verified by the general satisfaction expressed by the cell-separator donors. Although it is confirmed that the personal cost to the donor is greater, it involves, on the other hand, a greater commitment, a positive evaluation of the more intimate involvement of the donor, and an increase in self-esteem. Since it could not be proven that there is an increase in the amount of stress during cell-separator donation, it also seems plausible that no clear decrease in stress would be observed after repeated donations. On the whole, it seems that the cell separator is well accepted by the donors. The extent of experienced stress is related to the donor's habitual anxiety and negative expectations. Since negative expectations can be influenced, it is to be expected that an informative conversation in a quiet atmosphere would further decrease the stress experienced.

Adaptation, Psychological↗
PubMed1987

A simple and reproducible staining procedure to assess characteristic effects of some fixatives.

The standardized Romanowsky-Giemsa-Stain, adapted for use in histology, is recommended as a suitable technique to assess effects of fixatives. The stain consists of two dyes only--Azure B and Eosin Y--but gives a polychrome and reproducible staining pattern. Most important is the colour purple which results from Azure B-Eosin Y molecular interaction. A collection of fixative effects on the RG-staining pattern is given. They are not easily revealed by other equally simple histochemical techniques. Of special interest is the fixative-dependent development of the colour purple on various biological substrates. For instance, both formaldehyde and acrolein allow the generation of this colour on collagen fibers but only after formaldehyde, hardly after acrolein, will the full colour purple appear on chromatin. A list of substrates, RNA among them, is presented which will not stain purple after any of the fixatives employed. The results are briefly discussed.

Animals↗