Biomedical subjects

V Weisbach

Publications and source records attributed to V Weisbach.

At least 19 recordsLinked to original sources

PubMed1992

Bone marrow processing with the Fresenius AS 104: initial results.

Prior to purging, cryopreservation, or ABO-incompatible bone marrow (BM) transplantation, we have concentrated 23 BM harvests using a modification of the "grancollect-protocol" and the recently available bone marrow stem cell (BMSC) protocol of the Fresenius AS 104 cell separator with the P1-Y set. Within 40-70 minutes, the initial marrow volume of 922 ml (+/- 408 ml) was processed two to three times. A mean of 59% (+/- 20%) of the initial mononuclear cells was recovered in a mean volume of 119 ml (+/- 31 ml). The recovery of clonogenic cells, measured by CFU-GM assays, was 98% (+/- 80%). Red blood cells in the BM concentrates were reduced to 8% (+/- 4%) of the initial number. The procedure was efficient and yielded a BM cell fraction suitable for purging, cryopreservation, and transplantation. All transplanted patients showed fast and sustained engraftments after autologous or allogeneic BM transplantation.

Bone Marrow Cells↗

PubMed1992

Bone marrow purging prior to autologous transplantation.

Our data suggest that ex vivo bone marrow purging using monoclonal antibodies (MoAbs) and sheep-anti-mouse immunobeads (SAM beads) prior to autologous bone marrow transplantation (ABMT) allows satisfactory tumor cell reduction without critical stem cell losses. Nevertheless, there is only a reduction but no elimination of tumor cells. The consequences will have to be clinically discussed.

Antibodies, Monoclonal↗

PubMed1992

[Effect of leukocyte depleting polyester filters on thrombocytapheresis concentrates].

We studied platelet loss, leukocyte depletion, T/B cell ratio, platelet morphology and platelet function (aggregation, hypotonic shock reaction, retention and retraction) prior to and after filtration through two different polyester filters (Sepacell PL-5A, Pall PL100) as well as the posttransfusional platelet increment 1 h after transfusion in 8 pairs of single-donor platelet concentrates (Cobe Spectra, Fresenius AS 104). Leukocyte depletion was effective (>99.9%) and platelet loss acceptable in both filters, all tests showing no indication of a diminished platelet function by filtration.

Blood Component Transfusion↗

PubMed1992

[Autologous blood donation and erythropoiesis].

Autologous blood donation before elective surgery has been widely endorsed as good transfusion practice. Although only 6% of patients undergoing elective orthopedic surgery are unable to donate 3 autologous units, 40% cannot donate 4 units because they become anemic. According to the results of our study this must be due to different problems of bone marrow dynamics, which cannot be overcome by unselected use of human recombinant erythropoietin.

Adult↗

PubMed1992

[Hemoglobin follow-up of orthopedic autologous blood transfusion patients].

Patients undergoing autologous donation prior to elective orthopedic surgery show better Hb values during the perioperative period compared to those without autologous donation, all patients in both groups receiving no homologous transfusion. The widely assumed improvement of Hb regeneration during the postoperative period according to an erythropoiesis stimulated by preoperative autologous donation is not supported by our data.

Adult↗

PubMed1992

[Attempts in developing a standardized test system of immunologic reactivity].

Stimulation of lymphocytes with mitogens and antigens is an established model for in vitro testing of immunoreactivity. Due to the great variability of blastogenic response the interpretation of these results is difficult. Our results suggest that multivariate experiments and statistics improve the interpretation.

Antigens, Bacterial↗

PubMed1992

[Acquired autoimmune hemolytic anemia after liver transplantation by "auto"-anti-A and "auto"-anti-P1].

A 47-year-old man (group A) received a cadaver liver from a group 0 donor. On day 8 after the transplant the recipient developed severe immune hemolysis and showed a positive direct antiglobulin test due to two antibodies (anti-A and anti-P1) of transplant donor origin. The possible mechanisms involved in "autoantibody" formation in the recipient are discussed.

ABO Blood-Group System↗

PubMed1992

[Anti-M after transfusion as an indication of a genetic variant of the MN locus].

We report a case of an anti-M antibody (titer 128) and MN red blood cells (RBC) in a 76-year-old female German patient. In our case, however, RBC showed weak reactions to human anti-M compared with strong reactions using rabbit anti-M. Papain treatment destroyed the RBC reactivity to human anti-M whereas the strong reactivity to rabbit anti-M was unchanged. This pattern was also demonstrable in the patient's son and grandson. Our results indicate the existence of a rare allele at the MN locus in this family.

Aged↗

PubMed1992

[Follow-up of blood donors with indeterminate reaction to anti-HIV 1/2 EIA or isolated detection of antibodies to HIV-1 core antigens (anti-p24)].

Over a period of 20 months we identified 10 voluntary blood donors with indeterminate reactions in anti-HIV 1/2 EIA tests. Western blot (WB) patterns of 6 of these 10 donors showed isolated core antibodies (anti-p24), in 4 cases WB patterns were negative. After a median follow-up period of 58 weeks (range 12-93) we have not seen a case of typical seroconversion.

AIDS Serodiagnosis↗

PubMed1992

Cutaneous toxicity of high-dose carboplatin, etoposide and ifosfamide followed by autologous stem cell reinfusion.

Forty patients with germ cell tumors were treated with carboplatin 1500-2000 mg/m2, etoposide 1200-1600 mg/m2 and ifosfamide 0-10 g/m2 plus mesna followed by autologous stem cell reinfusion. A pruritic maculopapular rash was observed in 10 patients usually starting on the last day of chemotherapy. Lesions remained localized to the extremities in four patients. In six they became confluent and progressed also involving the trunk and face. Facial edema and painful swelling of hands and feet also occurred in this latter group. No ulcerations or bullae formation were seen and changes resolved spontaneously in all patients within 3 weeks leaving marked hyperpigmentation in involved areas. Renal function declined in nine of 10 patients concomitantly with evolving cutaneous changes, but recovered in all except one. Cutaneous side effects were more frequent with increasing doses of etoposide and carboplatin and in patients with deteriorating renal function. Plasma concentrations during high-dose chemotherapy should be monitored to avoid excessive serum levels and toxicity, especially in patients at risk of renal dysfunction.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1992

[Changes in thrombocytapheresis concentrations caused by leukocyte depletion with polyester filters].

We studied platelet loss, leukocyte depletion, T/B-cell-ratio, platelet morphology and platelet function (aggregation, hypotonic shock reaction, retention and retraction) prior to and after filtration through two different polyester filters (Sepacell PL-5A, Pall PL100) as well as the posttransfusional platelet increment 1 h after transfusion in 8 pairs of single donor platelet concentrates (Cobe Spectra, Fresenius AS 104). Leukocyte depletion was effective (greater than 99.9%) and platelet loss acceptable in both filters, all tests showing no indication of a diminished platelet function by filtration.

Hemofiltration↗

PubMed1992

[Erythropoiesis and iron metabolism in autologous blood donation].

Autologous blood donation before elective surgery has been widely endorsed as good transfusion practice. Although only 6 percent of patients undergoing elective orthopedic surgery are unable to donate 3 autologous units, 40 percent cannot donate 4 units because they become anemic [1,2]. According to the results of our study this must be due to different problems in bone marrow dynamics, which cannot be overcome by unselected use of human recombinant erythropoietin alone [3].

Adult↗

PubMed1991

[Stem cell separation with different cell separators].

For some years, there has been an increasing success in transplanting peripheral blood stem cells (PBSC) instead of autologous bone marrow in patients suffering from different malignancies. While collecting PBSC for autologous transplantation, we compared four different separation techniques and three different cell separators (COBE Spectra, Fresenius AS 104, Haemonetics V50) routinely used for platelet production. Our results suggest that continuous flow separators seem to have some advantage over discontinuous flow machines in harvesting PBSC.

Blood Cell Count↗

PubMed1991

[Clinical use of peripheral stem cells for autologous transplantation].

Peripheral blood derived hematopoietic stem cells (PBSC) have been transplanted successfully to eight patients suffering from different malignancies. The separations were started during chemotherapy-induced cytopenia and large volumes of peripheral blood were processed. Using this separation concept, it was possible in all cases to obtain the stem cell amount necessary for hematopoietic reconstitution.

Blood Cell Count↗

PubMed1991

[Risks of autologous blood transfusion].

Underutilization of autologous blood for transfusion is widespread. Our results suggest that this problem could only gradually be corrected, as some patients show insufficient erythropoietic recovery after a predeposit autologous donation.

Adult↗

PubMed1990

[ABO blood groups and platelet transfusion].

Platelet transfusion without regard for AB0 compatibility is controversially discussed. Therefore, we studied the success of 136 AB0 compatible and 52 incompatible platelet applications in 37 patients. Our results suggest, that AB0 matching can improve the response of platelet transfusion.

ABO Blood-Group System↗

PubMed1990

[Can thrombocyte crossmatching improve the efficiency of platelet transfusion?].

We did crossmatching in 220 transfusions of single donor platelet concentrates using the purchaseable solid phase immunoassay Capture-P (Immucor, Rödermark, FRG), checking posttransfusion response by calculating the corrected count increment (CCI). Our results show that posttransfusion response in transfusions of ABO major incompatible platelet concentrates is virtually reduced only in those transfusions accompanied by a positive crossmatch in Capture-P. As Capture-P can detect IgG antibodies only, positive test results could well be due to a reaction of recipient immune isoagglutinins with ABH antigens expressed on donor platelets, therefore.

ABO Blood-Group System↗

PubMed1990

[Stem cell concentrates in autologous transplantation].

For some years, there has been an increasing success in transplanting PBSC instead of autologous bone marrow in patients suffering from leukemic diseases. In healthy cytapheresis donors, we achieved peripheral blood mononuclear cell (PBM) recoveries of 74%, using a discontinuous flow separation technique (Haemonetics V50, Lymphosurge). At the moment, we have collected PBSC from 4 patients (3 AML, 1 ALL) in 28 cytapheresis procedures ranging from 12.9% to 80.1% (mean: 40.1%), whereas stem cell recoveries, defined by CFU-GM, were significantly better (mean: 66%). At present, one of these patients has been transplanted with PBSC alone, receiving 2.11 x 10(8) PBM/kg with 2.8 x 10(4) CFU-GM/kg. His posttransplantation cytopenia was shorter compared to other patients undergoing autologous bone marrow transplantation. The period of disease-free survival is now more than eight months while he is completely reintegrated into social and working life.

Blood Cell Count↗