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Biomedical subjects

W Luboldt

Publications and source records attributed to W Luboldt.

14 recordsLinked to original sources
PubMed1991

Fc receptor blocking antibodies after active immunization for the treatment of recurrent spontaneous abortion.

In a prospective study 140 couples who had at least three spontaneous abortions (RSA) were studied for the presence of Fc receptor blocking antibodies detected by the erythrocyte antibody rosette inhibition (EAI) assay, for anti-paternal cytotoxic antibodies (APCA), and for mixed lymphocyte culture inhibiting (MLCI) antibodies before and after active immunization with paternal lymphocytes. The comparative analysis revealed the EAI assay to possess a higher sensitivity than the APCA and/or MLCI tests in monitoring the specific immune response after active immunization. The success of pregnancy in EAI positive post-immunization patients was not influenced by the presence or absence of APCA or MLCI. In the light of a successful pregnancy outcome of 85.7% (n = 37) in this study we conclude that the monitoring of Fc receptor blocking antibodies is useful in active immunization protocols for RSA patients.

Abortion, Habitual↗
PubMed1991

[Plateletpheresis with the new cell separator A 201 (Baxter)].

This report deals with our first experiences in testing the new system A 201 (Baxter Fenwal Division) for plateletpheresis in routine application. The apparatus developed from the well-known plasmapheresis equipment Autopheresis C only requires a single venipuncture and uses two separation devices. The platelet cell device produces a primary platelet concentrate. After the donor's disconnection, the platelet-containing plasma is separated into 400 ml of red cell and leucocyte-free plasma and the platelet concentrate, which is done by a rotating membrane filter of the same instrument. Plateletpheresis was performed on 34 healthy donors (26 male and 8 female), formerly experienced by other apheresis procedures. Different samples were drawn from the donors before, during and after apheresis. In comparison with other apheresis procedures there were no significant differences in the harvested platelets (3 +/- 0.7 x 10(11), but the preparations showed a higher contamination of leucocytes (3.7 +/- 3.7 x 10(8). This means a considerable disadvantage and requires improvement. Yet the advantages of this separator are obvious: Reduction of needed anticoagulation to only 6% of processed blood volume, single needle technique, safety of operation and, due to less size, more mobility.

Blood Donors↗
PubMed1991

[Thrombocytapheresis with the (Baxter) A 201 cell separator--initial data of biocompatibility].

The cell separator A 201 was a new platelet pheresis prototype designed to carry out a discontinuous apheresis while platelet-rich plasma (PRP) is sampled continuously. After donation, a platelet concentrate (PC) and a fresh frozen plasma was collected from the PRP by the plasma cell-C device. The PC contained 2.6 +/- 0.7 x 10(11) platelets with a leucocyte contamination of 3.9 +/- 3.9 x 10(8) and an erythrocyte contamination of 3.0 +/- 3.0 x 10(8). The fresh frozen plasma was nearly cell-free. Prior, during and after apheresis we analysed hemolysis and coagulation parameters. There was no evidence for hemolysis. The analysis of the coagulation factors and of the Thrombin-Antithrombin III-complex, however, gave a hint of an activation of coagulation.

Biocompatible Materials↗
PubMed1990

Further characterization of the EAI factor induced by alloimmunization for treatment of recurrent abortion.

In order to remove the EAI "blocking" activity, EA inhibition positive sera from patients with recurrent abortions were absorbed after alloimmunization with paternal lymphocytes by the lymphoblastoid cell line (LCL) of the husband. To avoid non-specific binding via the Fc-receptor, the cells were first fixed with 0.05% glutaraldehyde. Absorption was performed for 3 h at 4 degrees C. For subsequent elution, the cells were incubated with 0.1 M glycine-HCl, pH 2.3, for 30 min at 4 degrees C. After each step, EAI assay was carried out to determine the "blocking" activity in the supernatants. Furthermore, 10% SDS-PAGE and immunoblotting with goat antihuman IgG of the whole serum and the supernatants were performed. The results obtained give evidence that the EAI "blocking" activity can be absorbed by and eluted from the LCL of the immunizing husband, and is due to an IgG antibody directed against an antigen present on the LCL. Further absorption experiments with trophoblast cells will show whether this antigen is also displayed by the trophoblast.

Abortion, Habitual↗
PubMed1990

[Comparison of 3 types of cell separators].

The aim of the present investigation was to compare the efficiency of three commercially available cell separators with respect to thrombocyte yields. In addition, advantages and disadvantages of the different cell separator types were studied. There was no difference in the total number of platelets harvested by the different cell separators. In contrast the thrombocyte count of packages from the V 50 device was significantly lower as compared with the others (p = 0.05). We conclude that the cell separators tested are comparable with respect to the efficiency of processing platelet concentrates. However, the larger amount of plasma of the V 50 might be a disadvantage in some circumstances. The AS 104 has advantages in the handling and the duration of cell separation. In addition it offers technical improvements such as control of the ACD flow by a separate adjustable pump and a hemolysis detector.

Blood Transfusion↗
PubMed1990

[Experiences with transfusion of CMV tested blood preparations after bone marrow transplantation].

Cytomegalovirus infections are frequent and often life-threatening in bone marrow transplant recipients. Among 112 of our patients after bone marrow transplantation (BMT), 28 developed clinical symptoms or laboratory test results of CMV infection, and 15 of them died. In our experience blood cell substitution with products from CMV negative blood donors does not completely prevent CMV infections. Other factors like disturbances of immunoreconstitution after BMT are relevant in promoting the development of CMV disease.

Antibodies, Viral↗
PubMed1990

[Erythrocyte substitution and isoagglutinin titer following ABO-incompatible bone marrow transplantation].

About 2 or 3 weeks after transplantation, even ABO-Incompatible bone marrow shows a successful graft. Haemopoiesis is not always free of problems. Suppression of erythropoiesis is caused by persistently incompatible agglutinins. Patient's well-being is limited by longer periods of low levels of haemoglobin concentration. Long-lasting need for transfusions is related to the well-known risk of infections. A procedure to eliminate the residual titers of alloantibodies should be discussed in time with the staff of the transfusion department.

ABO Blood-Group System↗
PubMed1989

[Deep freezing of blood with special reference to autologous blood donation].

The preoperative collection of a patient's blood for later retransfusion during operation is the only way to avoid the risks of immunization and infection by homologous blood. If larger volumes of blood are needed the storage of the red cells by deep freezing techniques (liquid Nitrogen) ist very helpful. To get such a deposit of autologous blood, especially from patients with rare antigens or antibodies against public antigens, depends upon some criterias. The patient must be in sufficiently good condition for undergoing several phlebotomies in shorter intervals than a normal donor. The equipment of freezing and thawing may be more expensive and finally autologous transfusion programmes require more planning and time than ordinary blood donation. Therefore the combination of such a programme with preservation by freezing will be reserved for certain centres, even in the near future.

Blood Preservation↗
PubMed1975

[Chances of reducing the formation of immune antibodies after massive transfusions in open heart surgery (author's transl)].

Children, young people and women at the age of possible maternity form the majority of patients operated by extracorporal circulation. A longterm planning of these operations should also have donor in call, who are compatible with the patients' Rh groups and Kell antigens. Having practiced such a selection of donors we succeeded in reducing the formation of immune antibodies. 6 out of 330 patients had antibodies, but 4 had been sensibilized before operation. In the case of the other 2 it would not be excluded that they might have been immunized a long time ago. We emphasize the importance of hemodilution, strict indication of every postoperative therapy with red cells and the autologous transfusion.

ABO Blood-Group System↗