Biomedical subjects
Publications and source records attributed to W Mempel.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A 22-year-old, blood group O, Rh-positive (R2r) man received bone marrow from his blood group A, Rh-negative (rr), HLA-identical sister for treatment of acute lymphocytic leukemia. The patient's pretransplantation serum contained anti-A in a low concentration; therefore, plasmapheresis was not done prior to transfusion of bone marrow. To prevent graft-versus-host disease, bone marrow was incubated with absorbed rabbit antithymocyte globulin prior to infusion, and the patient was treated with methotrexate in the posttransplantation period. After transplantation, the patient received 6 units of group O, Rh-negative (rr) packed red cells from random donors and 6 units of platelets from the marrow donor. Three months after transplantation, 0.5 percent of his red cells were still of the host's type (group O, Rh-positive), as detected by immunofluorescence technique in blood smears. Four months after transplantation, three different Rh antibodies--anti-D, -E, and -G--were detected. Since the patient received only Rh-negative red cell transfusions, it is concluded that he was immunized to his original red cells.
BACKGROUND: The shelf life of liquid-stored platelet concentrates is limited to 5 days. Therefore, much work has been carried out in an attempt to establish the optimum method for cryopreservation. Among the various cryoprotectants, dimethyl sulfoxide (DMSO) has been shown to be the most effective. However, DMSO-frozen platelets are characterized by a number of cell lesions. This report describes metabolic and functional changes that should give rise to some concern about the functional integrity of these cells. STUDY DESIGN AND METHODS: Single-donor platelet concentrates were frozen in liquid nitrogen by use of DMSO (5%). After thawing, the cells were washed and resuspended in autologous plasma. Before, during, and after the freezing process, samples for analysis of metabolic measures (e.g., pH; calcium, potassium, and lactate dehydrogenase concentrations; plasma complement factors) and functional measures (e.g., aggregometry, in vitro bleeding time, alpha-granule membrane protein-140 expression) were taken. RESULTS: Mean platelet volume increases during the deep-freezing process. Potassium, calcium, and lactate dehydrogenase are released from the intracellular space to the extracellular space. A strong activation of complement, which is mainly due to the addition of DMSO, is observed. Platelets become activated as indicated by the expression of alpha-granule membrane protein-140. Accordingly, decreased platelet function can be observed. CONCLUSION: DMSO-frozen platelets are characterized by several metabolic and functional changes. Although these cells have been shown to exert hemostatic effects in vivo, it is conceivable that those effects could be improved by further development of platelet-freezing techniques.
Transfusion-induced hemochromatosis remains a major therapeutic complication in the management of patients with chronic hemolytic anemias. Red cell units harvested with blood cell separators have an average estimated mean cell age of 30 days, compared to 60 days for unfractionated blood. Our initial experience with transfusion of neocytes indicates that the amount of transfused erythrocytes can be reduced on 60 per cent. Further studies must demonstrate the clinical benefit. When combined with modern iron chelator regimens, it may be possible to achieve consistently negative iron balance prior to the onset of hemochromatosis which would allow patients to probably lead a normal life-span.
Storage of single-donor platelet concentrates is currently limited to 5 days. During this period, however, numerous morphologic and biochemical changes have been observed. These changes result in functional impairment of stored platelets. The present study describes increased binding of a monoclonal antibody against GMP 140 on the surface of stored single-donor platelets revealing an activation process. In contrast, binding of monoclonal antibodies directed against glycoprotein complex (GP) IIb-IIIa and ligand-induced binding site (LIBS1) is slightly diminished during storage. When platelets are stimulated with ADP GMP 140, GP IIb-IIIa, and LIBS1 are expressed to a higher extent than on the surface on nonstimulated platelets. The quantity exposed, however, depends upon the storage time. It is significantly reduced when platelets are stored for longer than 1-2 days. The present data indicate that storage of single-donor platelet concentrates affects fibrinogen binding, cell to cell cohesion, and release reaction. The results are in good agreement with conventional aggregation and in vitro bleeding time measurements.
Clinical and experimental studies indicate, that blood transfusion can modify the recipient's immune system. While beneficial to renal allograft survival, these immunomodulating effects may, however, prove detrimental to cancer patients. Recently, an adverse relationship between blood transfusion and cancer recurrence was reported in colon, lung, breast, kidney and gastric cancer. Moreover, a higher postoperative infection rate was observed when blood units were administered intraoperatively. We retrospectively reviewed the records of 174 patients with squamous cell carcinoma of the larynx undergoing curative resection between 1979 and 1985. One hundred and forty-one patients received blood transfusions, 33 did not. Recurrence rate (16.7%) was significantly related to clinical stage (p = 0.008) and lymph node status (p = 0.000); cumulative survival time depended significantly on clinical stage (p = 0.003), lymph node status (p = 0.004) and tumor size (p = 0.017). In contrast, when corrected for these baseline prognostic factors, no significant correlation could be detected between blood transfusion and cancer relapse. Also, survival time did not depend on blood transfusions. No correlation could be found between postoperative infection rate and intraoperative application of blood transfusion (p = 0.694). The present study does not support the hypothesis that blood transfusion adversely affects the prognosis of patients with laryngeal cancer. It indicates, that risk factors other than blood transfusion have a greater influence on recurrence and survival time.
BACKGROUND: The effect of blood transfusion on prognosis of resected cancer patients has been debated controversially. Therefore, we raised the hypothesis that transfusion-associated immunomodulation affects minimal residual disease after curative tumour resection, an unknown and uncontrolled phenomenon in all former studies which might significantly influence long-term prognosis. PATIENTS AND METHODS: 104 patients of a prospective study with curatively resected gastric cancer were stratified according to the immunocytochemical detection of disseminated tumour cells in bone marrow and the prognostic impact of allogeneic blood transfusion was tested. Multiple sequential bone marrow aspirations during follow-up were performed in 74 patients to investigate the blood transfusion effect on long-term development of this systemic disease component. RESULTS: Whereas in patients with tumour cell detection in bone marrow a significant association of blood transfusion and survival was seen (P = 0.048; relative risk 2.91; 95% CI 1.51-5.61), this was not found in patients without disseminated tumour cells (P = 0.129). Quantitative development of tumour cells in bone marrow during follow-up demonstrated a significant quantitative increase of tumour cells in transfused patients only (P = 0.028). CONCLUSION: These findings might explain the contradictory results of recent studies and suggest that the prognostic effect of transfusion is mediated through an impact on minimal residual disease in resected cancer patients.