Developments in the field of internet bring along the developments in education. The increase in the importance of the use of computers and the internet in the field of education necessitated the measurement of this dimension in the tests which are applied in wide scales. The research problem consists of the effect of the computer access and aim of computer use of 15 year-old students who participated in the computer part of the Programme for International Student Assessment (PISA 2006) over their achievements in science. The variant that best processes the students' achievement in science and the most important factor t hat affects achievement is students' access to computers.
Summary:The aim of this study was to study the usefulness of erythrocyte antigen (EA) measurement to study engraftment after allogeneic HSCT. In all, 31 consecutive patients receiving HLA-identical bone marrow (BM) (n ¼ 13) or peripheral blood stem cells (n ¼ 18) were investigated. Apart from the ABO group, 15 EAs representing six minor blood groups were followed by the simple tube agglutination technique. A total of 20 (64.5%) patients received ABOidentical, eight (25.8%) received ABO minor and three (9.7%) received ABO major mismatched grafts. In all, 29 patients were followed for a median of 12 (6-16) months; 65% of the patients expressed donor type EA 1 month and almost all did so 6 months after transplant. Reticulocyte engraftment was significantly shorter than EA engraftment (median 18 vs 35 days) (P ¼ 0.001). Patients who received PB stem cells showed significantly faster EA and reticulocyte engraftment than patients who received BM stem cells (P ¼ 0.038 and 0.025). ABO compatibility did not have an impact on reticulocyte and EA engraftment (P ¼ 0.4 and 0.55). The earliest donor type EA detected was from the Rh and Kidd system. These data suggest that EA and reticulocyte assays are useful in monitoring engraftment. 4 Flow cytometric analysis using monoclonal antibodies directed against blood group antigens enabled sensitive evaluation of dual RBC populations. 5 Our aim was to study a simple tube hemagglutination method for monitoring RBC repopulation following HSCT. In addition, we evaluated the disappearance of recipient-derived RBC antigens and appearance of donorderived antigens after transplantation, and correlated RBC antigen engraftment with reticulocyte counts after AHSCT. Patients and methods PatientsA total of 31 consecutive HSCT patients were studied. They consisted of 11 females and 20 males with a median age of 36 years (range 18-51). The underlying diseases were chronic myeloid leukemia in 18, acute leukemia in 11, severe aplastic anemia in one and renal cell carcinoma in one patient. In all, 13 of the patients received bone marrow (BM) and 18 received peripheral blood stem cells (PBSC) from their HLA-identical siblings. Eight of the patients received minor and three received major ABO-incompatible grafts. Table 1 shows the patient and donor characteristics. Transplantation procedureThe patients were conditioned by ablative cyclophosphamidebased regimens (81%) or fludarabine-based reduced intensity regimens. 6 All the patients received short-course methotrexate and cyclosporine for GVHD prophylaxis. All the donorrecipient pairs were CMV-seropositive. Recombinant human G-CSF was used until neutrophil engraftment after day þ 1 in BM group, but not in the PBSC. All the blood products were leucofiltered and irradiated. The pretransplant evaluation of the mismatched patient-donor pairs, the decision for erythrocyte and plasma depletion of the harvest and posttransplant transfusion policy were designed by our transplant center's transfusion medicine consultant (Dr Arslan), according to recently pu...
Objective:Any erythrocyte transfusion among humans having type A or B blood groups is impossible due to antibodies causing fatal transfusion complications. A cross-match test is performed to prevent immune transfusion complications before transfusion. Our hypothesis is that the fragment antibody (Fab) part of the antibody (incomplete antibody) may be used to prevent an immune stimulus related to the complete antibody. Therefore, we designed a pilot study to evaluate the effectiveness of these incomplete antibodies using cross-match tests.Materials and Methods:Pepsin enzyme and staphylococcal protein A columns were used to cut anti-A and anti-B monoclonal antibodies and purify their Fab (2) fragments, respectively. An Rh-positive erythrocyte suspension with purified anti-A Fab (2) solution and B Rh-positive erythrocyte suspension with purified anti-B Fab (2) solution were combined correspondingly. Cross-match tests were performed by tube and gel centrifugation methods. The agglutination levels due to the anti-A and anti-B Fab (2) antibodies and their effects on the agglutination normally observed with complete antibodies were then measured.Results:No agglutination for the purified incomplete anti-A Fab (2) with A Rh+ erythrocyte and anti-B Fab (2) with B Rh+ erythrocyte combinations was observed in the tube cross-match tests. These agglutination levels were 1+ in two wells in the gel centrifugation cross-match tests. Fab (2)-treated erythrocytes were also resistant to the agglutination that normally occurs with complete antibodies.Conclusion:We determined that the Fab (2) fragments of antibodies may not only be used to obtain a mild or negative reaction when compared to complete antibodies, but they might also be used for decreasing ABO incompatibility. Incomplete antibodies might be a therapeutic option in autoimmune hemolytic anemia and they may also be used in solid organ or hematopoietic stem cell transplantation. Therefore, we have planned an in vivo study to prove these in vitro findings.
Recently, in an effort to reduce the transplant related mortality, AHCT with reduced intensity conditioning (RIC) have been developed. It has been reported that patients receiving RIC from an ABO-mismatched donor had more transplant-associated complications compared to ablative AHCT (BMT2001;28: 315, Transfusion2002; 42:1293, Transfusion2003; 43: 1153). In this single center, retrospective, historical case-matched study, we aimed to analyze the influence of ABO-incompatibility on transplant-related morbidity and mortality between ablative and RIC. Between 1988 and 2003, 39 patients underwent AHCT with RIC and only 14 were ABO-incompatible. Ten patients with ABO-incompatibility and having a regular follow-up for blood group typing were evaluated for immuno-hematological complications, such as acute or delayed-type hemolysis (DTH), pure red cell aplasia (PRCA), thrombotic thrombocytopenic purpura (TTP) and early transplant-related complications, were compared to 20 case control recipients having matched pretransplant characteristics and similar follow up, but myeloablative regimen, either bone marrow (BM) or peripheral blood (PB) stem cells infused. Patients’ characteristics are shown in table below. All the recipients and donors underwent a detailed pretransplant work up and all the recipients were followed twice a week post transplant by a transfusion specialist according to guidelines (BMT, 2001;28:315). Median follow-up was 195 days (range, 51–538d). We did not observe any acute hemolysis, but 11 experienced DTH. No significant differences were encountered among the three groups in terms of DTH (p=0.356). In all recipients having a major ABO incompatibility, the blood group switched to donor type, but 50% of the patients with minor ABO-incompatibility still had either their antigen persistency or the appearance of donor-derived isoagglutinins. We observed mild (n=1, BM group) and severe pure red cell aplasia (n=1, RIC group) in two patients having a major ABO-incompatibility. TTP was developed in one patient with major ABO-incompatibility. In conclusion, we did not observe any difference between ablative AHCT and RIST in ABO incompatible patients in terms of immuno hematological complications in contrast to published case series. In addition, we could not show any negative impact of ABO-incompatibility on the severity of acute GVHD and the rate of early transplant related mortality. Table Conditioning Ablative Reduced Intensity Source (patients) PB (n=10) BM (n=10) PB (n=10) Gender (M/F) 2/8 6/4 5/5 Median age (range) 34 (16–45) 31 (17–46) 33 (21–47) Diagnosis CML (2), AML (7), other (1) CML (2), AML (6), other (2) CML (4), AML (1), other (5) ABO-incompatibility Major 5 6 5 Minor 5 4 5 Delayed type hemolysis 5 (50%) (22,23,55,90,120) 2 (20%) (18,27) 4 (40%)(20,130,165,188) RBC transfusion (100 days) 3 (0–15) 4 (0–10) 5 (0–10) Median days of the independence from pRBC 7 (0–31) 18 (0–41) 7 (0–28) Median follow-up (days) 195 (90–538) 194 (63–467) 200 (51–511) Acute GVHD (grade II–IV) n (%) 3 (30%) 4 (40%) 4 (40%) TRM 100, n (%) 1 (%10) 1 (%10) 1 (%10)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.